Xavier is testing different types of planting soil to determine which type is most effective in growing blueberry bushes. He purchases two different brands of planting soil from a local store. Xavier applies Brand A to an area of the yard that receives full sunlight and Brand B to another area of the yard that is in partial sunlight. He waters the area with Brand B daily; he waters the area with Brand A every other day. At the end of the study, Xavier concludes Brand A is more effective in growing blueberry bushes. Why is his conclusion not valid?

Answers

Answer 1

Answer:

He did not control for lurking variables and their impacts on the results of his experiment. Amount of sunlight and water received are two outside variables(or confounding variables) that may impact the growth of his plants and influence the results. He needs to apply the same amount of sunlight and water to each plant within a different planting soil in order to rule out the influence of those two variables and test the sole effect of the soil brand on the plant growth. Otherwise, it would be hard to determine whether his plant growth was because of the soil brand or the different amounts of sunlight and water received

Answer 2

Answer:

Invalid

Step-by-step explanation:

Xavier did not control variables or the impacts of the results. Confounding variable being sunlight and water received are two outside variables that can impact growth influence results. Within a different planting soil, Xavier will apply the same amount of sunlight & water to each plant to rule out the influence of those two variables. The test for sole effect on the plant with growth otherwise be determine. Is the plant growth because of the soil brand or the different amounts of sunlight and water received? This could and will impaired the results of this experiment, therefore, making it invalid.


Related Questions

please help i am stuck on this assignment

Answers

Answer:

answer

x = -13/ 15, 0

Step-by-step explanation:

15x^2 + 13 x = 0

or, x(15x + 13) = 0

either, x = 0

or, 15x + 13 = 0

x = -13/15

Answer:

The answer should be C...............

imma sorry if I'm wrong

pls help with all the questions

Answers

Answer:

Step-by-step explanation:

Since, CD is an altitude, ∠CDB will be a right angle.

m∠CDB = m∠CDA = 90°

By applying triangle sum theorem in ΔABC,

m∠CAB + m∠CBA + m∠ACB = 180°

20° + m∠CBA + 90° = 180°

m∠CBA = 180° - 110°

             = 70°

Therefore, m∠CBD = 70°

By applying triangle sum theorem in ΔBCD,

m∠BCD + m∠CDB + m∠DBC = 180°

m∠BCD + 90° + 70° = 180°

m∠BCD + 160° = 180°

m∠BCD = 20°

m∠CAD = m∠A = 20°

m∠ACD = 90° - m∠BCD

             = 90° - 20°

m∠ACD = 70°

24. What are the intercepts of -3x + 5y - 2z = 60?
(-20, 0, 0), (0, 12,0), (0, 0, -30)

(-60, 0, 0), (0, 60, 0), (0, 0, -60)
(-180, 0, 0), (0, 300, 0), (0, 0, -120)
(-3, 0, 0), (0,5, 0), (0, 0, -2)

Answers

I choose (-20,0,0) , (0,12,0), ( 0,0,-30)

Will give brainliest answer

Answers

Answer:

Below.

Step-by-step explanation:

log  10  ( 100 )  =  2

Answer:

First one: log_10 (100) = 2 OR log (100) = 2

Second one: 5^-3 = 1/125

Step-by-step explanation:

Let's say the formula for a basic exponent equation is this:

a = b^x

a is the answer when you calculate b^x

b is the base

x is the exponent

Here's the log formula using those variables:

log_b (a) = x

As long as you know how to rearrange the numbers/variables, you are good to go:

100 = 10^2

a = 100

b = 10

x = 2

log_10 (100) = 2

You can also write this one as log (100) = 2 because when you put log by itself, it's assumed that the base thing already equals 10.

log_5 (1/125) = -3

a = 1/125

b = 5

x = -3

5^-3 = 1/125

Hope it helps (●'◡'●)

8th Grade Which expression is equivalent to 1/27​

Answers

Answer:

[tex]( \frac{1}{3})^{3} [/tex]

Step-by-step explanation:

There are many expressions that can be equivalent to 1/27.

For example, 2/54, 3/81 etc

But I think the expression you are looking for is

[tex] \frac{1}{27} = \frac{1 \times 1 \times 1}{3 \times 3 \times 3} = \frac{ {1}^{3} }{ {3}^{3} } = ( \frac{1}{3} )^{3} [/tex]

Hope this is helpful

A system of equations is said to beinconsistentif the system has no solution. Show by usingthe pivot operation that the following system is inconsistent. Is the system equivalent to asystem in canonical form?

x1 + x2 - 3x3= 7
-2x1 + x2 +5x3 = 2
3x2 - x3 = 15

Answers

Answer:

The system is inconsistent

Step-by-step explanation:

Given the matrix system solutions in the attachment, we can see that the coefficient of the matrix rank has become zero. This shows that it has no solution.

Draw a line representing the “rise” and a line representing “run” of the line. State the slope of the line in simplest form

Answers

Answer: The rise and run is the two point between each other on a line for example 1/2 rise over run. 1 is rise and 2 is run so y=mx +b the slope is m and the y int is b so

Y= 1/2x + 3 the 3 is going to be on the Y acis not the X its important not to mix the two. In other words go to 0,0 make a line go up.. the from 0,0 go doen the same length

Step-by-step explanation:

Need answers asap!!!!!!!!!!!!!!

Answers

Answer:

The answer is

x equal -243

Answer:

-243 is yr correct answer.

Step-by-step explanation:

(-3)^-5=1/x1/(-3)^5=1/x1/-243=1/xx= -243

hope it helps

stay safe healthy and happy...

in the pair of triangle, write the similarity statement and identify the postulate of theorem that justifies the similarity.​

Answers

Answer:

ΔEFG ~ ΔRPQ - Angle Angle Angle Theorem

ΔEFG ~ ΔRFQ - Side Side Side Proportional Theorem

Step-by-step explanation:

First set : using triangle sum theory to find missing angle. Letters should match congruent angles when creating statement.

Second set :

[tex]\frac{EG}{RQ}[/tex] = [tex]\frac{10}{12}[/tex] =  [tex]\frac{5}{6}[/tex]

[tex]\frac{EF}{RF}[/tex] =  [tex]\frac{15}{18}[/tex] =  [tex]\frac{5}{6}[/tex]

[tex]\frac{FG}{FQ}[/tex] =  [tex]\frac{20}{24}[/tex] =  [tex]\frac{5}{6}[/tex]

Find the points on the given curve where the tangent line is horizontal or vertical. (Assume 0 ≤ θ ≤ 2π. Enter your answers as a comma-separated list of ordered pairs.) r = 1 − sin(θ) horizontal tangent

Answers

The tangent to the curve at a point P (x, y) has slope dy/dx at that point. By the chain rule,

dy/dx = (dy/dθ) / (dx/dθ)

We're in polar coordinates, so

y (θ) = r (θ) sin(θ)   ==>   dy/dθ = dr/dθ sin(θ) + r (θ) cos(θ)

x (θ) = r (θ) cos(θ)   ==>   dx/dθ = dr/dθ cos(θ) - r (θ) sin(θ)

We're given r (θ) = 1 - sin(θ), so that

dr/dθ = -cos(θ)

Then the slope of the tangent to the curve at P is

dy/dx = (dr/dθ sin(θ) + r (θ) cos(θ)) / (dr/dθ cos(θ) - r (θ) sin(θ))

dy/dx = (-cos(θ) sin(θ) + (1 - sin(θ)) cos(θ)) / (-cos²(θ) - (1 - sin(θ)) sin(θ))

dy/dx = - (cos(θ) - sin(2θ)) / (sin(θ) + cos(2θ))

The tangent is horizontal if dy/dx = 0 (or when the numerator vanishes):

cos(θ) - sin(2θ) = 0

cos(θ) - 2 sin(θ) cos(θ) = 0

cos(θ) (1 - 2 sin(θ)) = 0

cos(θ) = 0   or   1 - 2 sin(θ) = 0

cos(θ) = 0   or   sin(θ) = 1/2

[θ = π/2 + 2   or   θ = 3π/2 + 2]   or   [θ = π/6 + 2   or   θ = 5π/6 + 2]

where n is any integer.

In the interval 0 ≤ θ ≤ 2π, we get solutions of θ = π/6, θ = 5π/6, and θ = 3π/2. (We omit π/2 because the denominator is zero at that point and makes dy/dx undefined.) So the points where the tangent is horizontal are themselves (√3/4, 1/4), (-√3/4, 1/4), and (0, -2), respectively.

The tangent is vertical if 1/(dy/dx) = 0 (or when the denominator vanishes):

sin(θ) + cos(2θ) = 0

sin(θ) + (1 - 2 sin²(θ)) = 0

2 sin²(θ) - sin(θ) - 1 = 0

(2 sin(θ) + 1) (sin(θ) - 1) = 0

2 sin(θ) + 1 = 0   or   sin(θ) - 1 = 0

sin(θ) = -1/2   or   sin(θ) = 1

[θ = 7π/6 + 2   or   θ = 11π/6 + 2]   or   [θ = π/2 + 2]

Then for 0 ≤ θ ≤ 2π, the tangent will be vertical for θ = 7π/6 and θ = 11π/6, which correspond respectively to the points (-3√3/4, -3/4) and (3√3/4, -3/4). (Again, we omit π/2 because this makes dy/dx non-existent.)

Type the expression that results from the following series of steps: Start with y times by 4 then add 9.

Answers

Answer:

4y + 9

Step-by-step explanation:

"y times 4" means 4y because 4*y = 4y

And then "add 9."

Which would be 4y + 9.

Answer:

4y + 9

Step-by-step explanation:

y times 4 = 4y

add 9 = + 9

Greatest to least 2,250 2,700 2,450 2,500

Answers

Answer:

sorting;

2,7002,5002,450 2,250

greatest = 2,700

least = 2,250

HAVE A NİCE DAY

Step-by-step explanation:

GREETINGS FROM TURKEY ツ

greatest: 2,700
2,500
2,450
least: 2,250

I need help with this

Answers

Answer:

156 degrees

Step-by-step explanation:

Bisects meand to cut into two equal halves.

That means 4x-2=3x+18.

Subtracting 3x on both sides gives x-2=18

Adding 2 on both sides gives x=20

If x=20, then 4x-2 equals 4(20)-2=78.

The other half is also 78 since the two angles were comgruent.

The whole angle is 78+78=156.

Which expression is equivalent to -9x-1y-9/-15x5y-3?

Answers

Answer: -9x-1y-9/

Step-by-step explanation:

Answer: b

Step-by-step explanation:

I really dont like edge

Can you answer this an help me with this question an others ??

Answers

Answer:

D. The y-intercept of the new graph would shift down 2 units.

Step-by-step explanation:

y = -9x + 3 has a y-intercept of 3 (0, 3).

y = -9x + 1 has a y-intercept of 1 (0, 1).

3 - 1 = 2

So, down two units.


Find the circumference of a circle with a diameter of 50 centimeters. Round your answer to the nearest
centimeter.


Answers

Given :-

Diameter of circle = 50 cm .

To Find :-

The circumference of the Circle.

Solution :-

We know that the circumference of the Circle with radius r is given by ,

=> C = 2πr .

Here r is 50cm .

=> C = 2 × 3.14 × 50 cm

=> C = 314 cm .

Hence the required answer is 314 cm .

Answer:

Step-by-step explanation:

b 75

I WILL MARK BRAINLIEST:))
Please translate this expression into a verbal expression 4(5j+2+j). (5 points)​

Answers

24j+8 because like terms 5j+j=6j*4=24j and 4*2 equals 8

In 2013, the Public Religion Research Institute conducted a survey of 1,033 adults, 18 years of age or older, in the continental United States. One of the questions on their survey was as follows:

Answers

Answer:

Probability[Number of people from church] = 0.26 (Approx.)

Step-by-step explanation:

Given:

Total number of adult in survey = 1,033

Missing information:

Number of people from church = 269

Find:

Probability[Number of people from church]

Computation:

Probability of an event = Number of favourable outcomes / Number of total outcomes

Probability[Number of people from church] = Number of people from church / Total number of adult in survey

Probability[Number of people from church] = 269 / 1,033

Probability[Number of people from church] = 0.2604

Probability[Number of people from church] = 0.26 (Approx.)

Exercise
a. I choose the correct option from Contain Questions
i Which of the following is a group set ?
(b) A happy person in the Village
(c) Simple Ex in the book (d) school age student
(Weekly​

Answers

Answer:

happy person in the village

Which function has no horizontal asymptote?

Answers

Answer:

[tex]{ \tt{f(x) = \frac{x - 1}{3x} }}[/tex]

Answer:

c

Step-by-step explanation:

edge

Questions 23 and 29: Use the following information to answer each question. A recent book noted that only 20% of all investment managers outperform the Dow Jones Industrial Average over a five-year period. A random sample of 200 investment managers that had graduated from one of the top ten business programs in the country were followed over a five-year period. Fifty of these outperformed the Dow Jones Industrial Average. Let p be the true proportion of investment managers who graduated from one of the top ten business programs who outperformed the Dow Jones over a five-year period.
23. Based on the results of the sample, a 95% confidence interval for p is:
a. (1.95, 3.15)
b. (0.0195, 0 .0315)
c. (0.190, 0.310)
d. (0.028, 0.031)
e. (0.195, 0.315)
f. We can assert that p = 0.20 with 100% confidence, because only 20% of investment managers outperform the standard indexes.
24. Suppose you had been in charge of designing the study. What sample size would be needed to construct a margin of error of 2% with 95% confidence? Use the prior estimate of pâ=0.2 for this estimate.
a. n=2401
b. n=1537
c. n=16
d. n=1801
e. n>30
Suppose you wish to see if there is evidence that graduates of one of the top ten business programs performs better than other investment managers. Conduct a hypothesis test. Use a level of significance of α=0.05
25. Which of the following pairs of hypotheses is the most appropriate for addressing this question?
a. H0: p=0.2
Ha: p<0.2
b. H0: p=0.2
Ha: pâ 0.2
c. H0: p=0.2
Ha: p>0.2
d. H0: p<0.2
Ha: p=0.2
e. H0: pâ 0.2
Ha: p=0.2
f. H0: p>0.2
Ha: p=0.2
26. How many measurements must you have in order to assure that p^ is normally distributed?
a. nâ¥30
b. nâ¥5
c. npâ¥10 and n(1âp)â¥10
d. npâ¥5 and n(1âp)â¥5
27. The value of your test statistic is:
a. 1.768
b. 0.039
c. 1.923
d. 0.077
28. The P-value of your test is:
a. 1.768
b. 0.039
c. 1.923
d. 0.077
29. Is there sufficient evidence to conclude that graduates from the top ten business programs perform better than other investment managers?
a. Yes. I rejected H0
b. Yes. I failed to reject H0
c. Yes. I accepted Ha
d. No. I rejected H0
e. No. I failed to reject H0
f. No. I failed to accept Ha

Answers

Answer:

https://www.chegg.com/homework-help/questions-and-answers/questions-23-29-use-following-information-answer-question-recent-book-noted-20-investment--q13619465

Step-by-step explanation:

this might help you

sin4x - cosx
---------------- = f(x) f^1(π/4) what is the derivative?
tanx

Answers

I think you are asked to find the value of the first derivative of f(x) at π/4. Given

[tex]f(x) = \dfrac{\sin(4x)-\cos(x)}{\tan(x)}[/tex]

use the quotient to differentiate and you get

[tex]f'(x) = \dfrac{\tan(x)(4\cos(4x)+\sin(x))-(\sin(4x)-\cos(x))\sec^2(x)}{\tan^2(x)}[/tex]

Then at x = π/4, you have

tan(π/4) = 1

cos(4•π/4) = cos(π) = -1

sin(π/4) = 1/√2

sin(4•π/4) = sin(π) = 0

cos(π/4) = 1/√2

sec(π/4) = √2

==>   f ' (π/4) = (1•(-4 + 1/√2) - (0 - 1/√2)•(√2)²) / 1² = -4 + 1/√2 + √2

An expression to convert 50 miles per hour to miles per minute is shown.

What value can be entered in the box to correctly make this conversion?

Answers

Answer:

[tex]{ \tt{ = \frac{50}{1 \times 60} }}[/tex]

Step-by-step explanation:

50 miles=50 miles

1 hour=60 minutes

50÷60

0.8333333333333333mile per minute

~1.0 mile per minute

A bottle maker believes that 23% of his bottles are defective. If the bottle maker is accurate, what is the probability that the proportion of defective bottles in a sample of 602 bottles would differ from the population proportion by less than 4%

Answers

Answer:

0.9802 = 98.02% probability that the proportion of defective bottles in a sample of 602 bottles would differ from the population proportion by less than 4%

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

A bottle maker believes that 23% of his bottles are defective.

This means that [tex]p = 0.23[/tex]

Sample of 602 bottles

This means that [tex]n = 602[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.23[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.23*0.77}{602}} = 0.0172[/tex]

What is the probability that the proportion of defective bottles in a sample of 602 bottles would differ from the population proportion by less than 4%?

p-value of Z when X = 0.23 + 0.04 = 0.27 subtracted by the p-value of Z when X = 0.23 - 0.04 = 0.19.

X = 0.27

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.27 - 0.23}{0.0172}[/tex]

[tex]Z = 2.33[/tex]

[tex]Z = 2.33[/tex] has a p-value of 0.9901

X = 0.19

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.19 - 0.23}{0.0172}[/tex]

[tex]Z = -2.33[/tex]

[tex]Z = -2.33[/tex] has a p-value of 0.0099

0.9901 - 0.0099 = 0.9802

0.9802 = 98.02% probability that the proportion of defective bottles in a sample of 602 bottles would differ from the population proportion by less than 4%

if the mean of a random variable X is 45 what will be the mean of the sampling distribution of the sample mean?

Answers

Answer:

The mean of the sampling distribution is always equal to the mean of the population.

The mean of the sampling distribution of the sample mean is 45.

Given that,

The mean of the random variable X is 45.We need to find out the mean of the sampling distribution.

Based on the above information, the calculation is as follows:

= mean of the random variable X

= 45

As the sampling distribution mean should always be equivalent to the population mean.

Therefore we can conclude that the mean of the sampling distribution of the sample mean is 45.

Learn more: brainly.com/question/521501

A car traveling 7/10 of a mile per minute will travel _ miles in 10 minutes

Answers

Answer:

7 miles

Step-by-step explanation:

* means multiply

7/10 * 10 = 7

Can someone please help me with this?!!!

Answers

Step-by-step explanation:

A.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7

Sam works at a shoe store. He earns $300 every week plus $15 for every pair of shoes that he sells. How many pairs of shoes would he need to sell to make $500 in a week?

Answers

Answer:

300 + 15x = 500

15x = 200

x = 200/15

x=13.333

14 pair of shoes

Step-by-step explanation:

Two cell phone companies charge a flat fee plus an added cost for each minute or part of a minute used. The cost is represented by C and the number of minutes is represented by t.
Call-More: C = 0.40t + 25 Talk-Now: C = 0.15t + 40

Answers

Answer:

The call more is cheaper than talk-now.

Step-by-step explanation:

The companies charge a flat fee plus an added cost for each minute or part of a minute used for two companies are as follows :

Call-More: C = 0.40t + 25 Talk-Now: C = 0.15t + 40

We need to find which company is cheaper if a customer talks for 50 minutes.

For call more,

C = 0.40(50) + 25 = 45 units

For talk-now,

C = 0.15(50) + 40 = 47.5 units

So, it can be seen that call more is cheaper than talk-now.

salve by gauss jueabis method if iteration mothere aitration
4X+0.024x2-0.08x3=8
0.09x1+3x2-0.15x3=9
0.04x1+-0.08x2+4x3=20

Answers

I dunno g u got this tho
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