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

HELPPPPPPP PLEASEEEEEEE

Answers

Answer:

150 dollars. if I am wrong correct me

Answer:

C and D

Step-by-step explanation:

15 to 30 galons at $9.95 to $21.00

the minimum amount can be found by calculating the minimum amount sold at a minimum price 15*9.95 = $149.25

the maximum amount can be found by calculating the maximum amount sold at a maximum price 30*21 = $630

there are 2 choices that are between 149.25 and 630, C, and D

What is an amount between $2 and $10?

Answers

Answer:

6

Step-by-step explanation:

8. Discount: An auto dealer paid $8730 for a
large order of special parts. This was not the
original price. The amount paid reflects a 3%
discount off the original price because the
dealer paid cash. What was the original price
of the parts?

Answers

Answer: 5,987

Step-by-step explanation:

find the exact value cos5pi/6

Answers

Answer:

[tex] - \frac{ \sqrt{3} }{2} [/tex]

Step-by-step explanation:

Unit circle

Identify the transformation that occurs to create the graph of g(x). g(x)=f(x)-7

Answers

Answer:

g(x) is obtained by shift the function f(x) down 7 units by subtracting 7 units from f(x).

Step-by-step explanation:

We are given that

[tex]g(x)=f(x)-7[/tex]

We have to identify  the transformation that occurs to create the graph of g(x).

To identify  the transformation that occurs to create the graph of g(x)

We will subtract the 7 from f(x).

Let f(x) be any function

[tex]g(x)=f(x)-k[/tex]

It means g(x) obtained by  shift the function f(x) down  k units by subtracting k units from f(x).

Therefore, g(x) is obtained by shift the function f(x) down 7 units by subtracting 7 units from f(x).

What angles can you construct using just a pair of compasses and a ruler?

Answers

Answer:

By using a pair of compasses and a ruler you can draw all angles

Problem: The height, X, of all 3-year-old females is approximately normally distributed with mean 38.72
inches and standard deviation 3.17 inches. Compute the probability that a simple random sample of size n=
10 results in a sample mean greater than 40 inches. That is, compute P(mean >40).
Gestation period The length of human pregnancies is approximately normally distributed with mean u = 266
days and standard deviation o = 16 days.
Tagged
Math
1. What is the probability a randomly selected pregnancy lasts less than 260 days?
2. What is the probability that a random sample of 20 pregnancies has a mean gestation period of 260 days
or less?
3. What is the probability that a random sample of 50 pregnancies has a mean gestation period of 260 days
or less?
4. What is the probability a random sample of size 15 will have a mean gestation period within 10 days of
the mean?
Know
Learn
Booste
V See

Answers

Answer:

0.1003 = 10.03% probability that a simple random sample of size n= 10 results in a sample mean greater than 40 inches.

Gestation periods:

1) 0.3539 = 35.39% probability a randomly selected pregnancy lasts less than 260 days.

2) 0.0465 = 4.65% probability that a random sample of 20 pregnancies has a mean gestation period of 260 days or less.

3) 0.004 = 0.4% probability that a random sample of 50 pregnancies has a mean gestation period of 260 days or less.

4) 0.9844 = 98.44% probability a random sample of size 15 will have a mean gestation period within 10 days of the mean.

Step-by-step explanation:

To solve these questions, 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

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

The height, X, of all 3-year-old females is approximately normally distributed with mean 38.72 inches and standard deviation 3.17 inches.

This means that [tex]\mu = 38.72, \sigma = 3.17[/tex]

Sample of 10:

This means that [tex]n = 10, s = \frac{3.17}{\sqrt{10}}[/tex]

Compute the probability that a simple random sample of size n= 10 results in a sample mean greater than 40 inches.

This is 1 subtracted by the p-value of Z when X = 40. So

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

By the Central Limit Theorem

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

[tex]Z = \frac{40 - 38.72}{\frac{3.17}{\sqrt{10}}}[/tex]

[tex]Z = 1.28[/tex]

[tex]Z = 1.28[/tex] has a p-value of 0.8997

1 - 0.8997 = 0.1003

0.1003 = 10.03% probability that a simple random sample of size n= 10 results in a sample mean greater than 40 inches.

Gestation periods:

[tex]\mu = 266, \sigma = 16[/tex]

1. What is the probability a randomly selected pregnancy lasts less than 260 days?

This is the p-value of Z when X = 260. So

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

[tex]Z = \frac{260 -  266}{16}[/tex]

[tex]Z = -0.375[/tex]

[tex]Z = -0.375[/tex] has a p-value of 0.3539.

0.3539 = 35.39% probability a randomly selected pregnancy lasts less than 260 days.

2. What is the probability that a random sample of 20 pregnancies has a mean gestation period of 260 days or less?

Now [tex]n = 20[/tex], so:

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

[tex]Z = \frac{260 - 266}{\frac{16}{\sqrt{20}}}[/tex]

[tex]Z = -1.68[/tex]

[tex]Z = -1.68[/tex] has a p-value of 0.0465.

0.0465 = 4.65% probability that a random sample of 20 pregnancies has a mean gestation period of 260 days or less.

3. What is the probability that a random sample of 50 pregnancies has a mean gestation period of 260 days or less?

Now [tex]n = 50[/tex], so:

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

[tex]Z = \frac{260 - 266}{\frac{16}{\sqrt{50}}}[/tex]

[tex]Z = -2.65[/tex]

[tex]Z = -2.65[/tex] has a p-value of 0.0040.

0.004 = 0.4% probability that a random sample of 50 pregnancies has a mean gestation period of 260 days or less.

4. What is the probability a random sample of size 15 will have a mean gestation period within 10 days of the mean?

Sample of size 15 means that [tex]n = 15[/tex]. This probability is the p-value of Z when X = 276 subtracted by the p-value of Z when X = 256.

X = 276

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

[tex]Z = \frac{276 - 266}{\frac{16}{\sqrt{15}}}[/tex]

[tex]Z = 2.42[/tex]

[tex]Z = 2.42[/tex] has a p-value of 0.9922.

X = 256

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

[tex]Z = \frac{256 - 266}{\frac{16}{\sqrt{15}}}[/tex]

[tex]Z = -2.42[/tex]

[tex]Z = -2.42[/tex] has a p-value of 0.0078.

0.9922 - 0.0078 = 0.9844

0.9844 = 98.44% probability a random sample of size 15 will have a mean gestation period within 10 days of the mean.

Please help. I'm stuck on this problem

Answers

Answer:

Step-by-step explanation:

[tex]h(t)=-16t^2+96t\\\\h(t)=-t(16t-96)[/tex]

[tex]96=2^5*3\\\\16=2^4\\\\h(t)=-t(2^5*3*t-2^4)=-2^4t(2^1*3*t-1)\\\\h(t)=-16t(6t-1)[/tex]

the b) part is easy do it!

A polygraph (lie detector) is an instrument used to determine if an individual is telling the truth. These tests are considered to be 90% reliable. In other words, if an individual lies, there is a 0.90 probability that the test will detect a lie. Let there also be a 0.045 probability that the test erroneously detects a lie even when the individual is actually telling the truth. Consider the null hypothesis, "the individual is telling the truth," to answer the following questions
a. What is the probability of a Type I error? (Round your answer to 3 decimal places.)
b. What is the probability of a Type II error? (Round your answer to 2 decimal places.

Answers

Answer:

A) P(Type I error) = 0.045

B) P(Type II) error = 0.1

Step-by-step explanation:

We are told that the reliability of the test is 90% reliable.

Also, we are told that the probability that the test erroneously detects a lie even when the individual is actually telling the truth is 0.045.

Thus;

A) To calculate the probability of type I error:

From statistics, in this question we can say that the probability of a type I error is the probability that the test will erroneously detect a lie even though the individual is actually telling the truth. Thus;

Probability of (type I error) = P(rejecting true null) = 0.045

B) For probability of type II error, it is defined as the error where we accept a null hypothesis that is false. We can say that it produces a false negative and the formula is;

P(Type II) error = 1 - reliability

Reliability in the question is 0.90

Thus;

P(Type II) error = 1 - 0.9

P(Type II) error = 0.1

Which is a correct statement about the description “two less than the quotient of a number cubed and sixteen, increased by eight” when n = 4?

Answers

Answer:

n = 4 is 10

hope it helps and have a good day


The table shows the proof of the relationship between the slopes of two perpendicular lines. What is the missing statement in step 2?

Answers

Answer:

[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex]

Step-by-step explanation:

Given

The attached proof

Required

Complete the missing piece

In (a), we have:

[tex]\triangle ABC \to \triangle CED[/tex]

This implies that, the following sides are similar:

[tex]AB \to CE[/tex]

[tex]AC \to CD[/tex]

[tex]BC \to ED[/tex]

An equation that compares the triangle can be any of:

[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex]

[tex]\frac{AB}{AC} = \frac{CE}{CD}[/tex]

.....

From the options;

[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex] is true

Suppose that you and a friend are playing cards and you decide to make a friendly wager. The bet is that you will draw two cards without replacement from a standard deck. If both cards are diamonds, your friend will pay you $296. Otherwise, you have to pay your friend $17.
What is the expected value of your bet?

Answers

Answer:

False because $296=$296

find the measures of m and n.

Answers

Answer:

m = 4

n = 5

Step-by-step explanation:

[tex]m + 8 = 3m\\\\m - 3m = - 8\\\\-2m = - 8\\\\m = 4[/tex]

[tex]2n - 1 = 9 \\\\2n = 9 + 1\\\\2n = 10\\\\n = 5[/tex]

solve the system of equation — 3х + бу = 9
5х + 7y = -49

Answers

Answer:

y = 64/3

x = -119/3

Step-by-step explanation:

3х + 6у = 9 => 5*3x+5*6у = 9*5 => 15x+30у=45 (1)

5х + 7y = -49 => 3*5x + 3*7y = -49*3 => 15x+21y=-147 (2)

(1)-(2) => 9y = 192 => y = 64/3

x = -119/3

At the Fidelity Credit Union, a mean of 5.8 customers arrive hourly at the drive-through window. What is the probability that, in any hour, more than 5 customers will arrive

Answers

Answer:

0.5217

Step-by-step explanation:

P(more than 5 customer arrive):

P(X>=6)=1-P(X<=5)=  1-∑x=0x e-λ*λx/x!= 0.5217

In triangle ABC , segment AB is congruent to segment CB . Which angles are congruent?​

Answers

Answer:

angles A and C are congruent

Least to greatest 22,755 20,564 2,3805

Answers

Least to greatest: 20,564 22,755 2,3805

Which function represents the graph below?

Answers

Answer:

The answer is the third one below

You have to find the value of k

Answers

Answer:

115

Step-by-step explanation:

Can I get the answer for those

Answers

Answer:

1) 5.64

2) 17.321

1) [tex]\frac{21}{28}[/tex]

2) [tex]\frac{16}{34}[/tex]

3) [tex]\frac{28}{35}[/tex]

4) [tex]\frac{32}{24}[/tex]

Step-by-step explanation:

SOH - CAH - TOA

Sin = [tex]\frac{O}{H}[/tex]   Cos = [tex]\frac{A}{H}[/tex]  Tan = [tex]\frac{O}{A}[/tex]      

O = opposite, A = adjacent, H = hypotenuse

First two,  use Pythagorean Theorem

If you want to calculate the angle on the last 4, use inverse of function and put in the ratio.

For example :

1) Tan Z = [tex]\frac{21}{28}[/tex]

   [tex]Tan^{-1}[/tex] ( [tex]\frac{21}{28}[/tex])

Z = 36.9°

Entering 38.00 into the Price of Sneakers field Entering 6.00 into the Price field Entering 3.00 into the Price of Leather field True or False: You will no

Answers

Answer:

This question seems incorrect.

Kindly take a look again and re-state it properly to enable me give the most accurate answer.

Thank you

The measure of each interior angle of reglar convex polygon is 150 How many sides it does have​

Answers

Step-by-step explanation:

Since an interior angle is 150 degrees, its adjacent exterior angle is 30 degrees.  Exterior angles of any polygon always add up to 360 degrees.  With the polygon being regular, we can just divide 360 by 30 to get 12 sides.

 

What is the range of the table of values

Answers

Answer:

Range: { 0,3,5,7,9}

Step-by-step explanation:

The range is the values that y takes

Range: { 0,3,5,7,9}

Now we have to find,

The range of the table of values,

→ Range = ?

Then the range will be the numbers that is in the Y column.

→ Range = ?

→ Range = (value that Y takes)

→ Range = 0,3,5,7,9

Therefore, the range is 0,3,5,7,9.

Find the slope of every line that is parallel to the line on the graph ob Enter the correct answer. 6 4 OOO DONE Clear al N ? (-8,0) 10-12 pop -6 ko 8 ४ 2 2 8 do​

Answers

Step-by-step explanation:

x=-6 y= 0

x0 y= -1

y=mx+b

b= -1

0= -6m -1

-6m= 1

m= -1/6

parallel lines have the same slope

slope = -1/6

please help i guess on a

Answers

Answer:

A = (2, 2)

B = (3, -1)

C = (-1, 0)

Step-by-step explanation:

To translate a point, you have to translate each individual point. At the bottom it shows <-2,3>, therefore you have to translate x 2 units to the left (because it's negative meaning the number is going away from 0, and 3 units to the right because 3 is a positive number.)

First Point A:

x: 4 - 2 = 2; y: -1 + 3 = 2

Second Point B:

x: 5 - 2 = 3; y: -4 + 3 = -1

Lastly, Point C:

x: 1 - 2 = -1, y: -3 + 3 = 0

I hope this helps!

The graph below is the graph of a function.
10
- 10
10
- 10
True
B. False

Answers

Answer:

hgfyjtdjtrxgfyfguktfkgh

Step-by-step explanation:

hgfytrdutrc

Marina spent $13.50 at the grocery store. She bought pears, kiwis, and pineapples. Pears cost $0.50 each, pineapples cost $1.50 each, and kiwis are $0.30 each. How many did she buy if she bought 9 more pears than pineapples and 2 fewer kiwis than pears?

Answers

Answer:

Number of pineapples= 10

number of pears = 19

number of kiwis = 10 -2 = 8

Step-by-step explanation:

Cost of a pear = $ 0.50

Cost of a pineapple = $ 1.5

cost of a kiwi = $ 0.3

Let the pineapples = p

Number of pears = 9 + p

Number of kiwis = p - 2

The cost is

0.15 p + 0.5 (9 + p) + 0.3 (p - 2) = 13.50

0.15 p + 4.5 + 0.5p + 0.3 p - 0.6 = 13.50

0.95 p = 9.6

p = 10

 

Answer: There is 3 pineapples, 12 pears and 10 kiwis

Hope this help :)

(a) The heights of male students in a college are thought to be normally distributed with mean 170 cm and standard deviation 7.
The heights of 5 male students from this college are measured and the sample mean was 174 cm.
Determine, at 5% level of significance, whether there is evidence that the mean height of the male students of this college is higher than 170 cm.
[6]
(b) (i) The result of a fitness trial is a random variable X which is normally distributed with mean μ and standard deviation 2.4 . A researcher uses the results from a random sample of 90 trials to calculate a
98% confidence interval for μ . What is the width of this interval?
[4]
(ii) Packets of fish food have weights that are distributed with standard deviation 2.3 g. A random sample of 200 packets is taken. The mean weight of this sample is found to be 99.2 g. Calculate a 99% confidence interval for the population mean weight.
[4]
(c) (i) Explain the difference between a point estimate and an interval
Estimate. [2]
(ii) The daily takings, $ x, for a shop were noted on 30 randomly chosen days. The takings are summarized by Σ x=31 500 and
Σ x2=33 141 816 .
Calculate unbiased estimates of the population mean and variance of the shop’s daily taking. [4

Answers

Answer:

the answer is 50 but I don't know if

Identify the transformation that occurs to create the graph of h(x).
H(x)=f(x+3)

Answers

Answer: The graph moved left 3 units.

(x, y) = (x - 3, y)

Solve this equation log3X + log3(x-6) = log3 7

Answers

Hello!

log₃(x) + log₃(x - 6) = log₃(7) <=>

<=> log₃(x * (x - 6)) = log₃(7) <=>

<=> log₃(x² - 6x) = log₃(7) <=>

<=> x² - 6x = 7 <=>

<=> x² - 6x - 7 = 0 <=>

<=> x² + x - 7x - 7 = 0 <=>

<=> x * (x + 1) - 7 * (x + 1) = 0 <=>

<=> (x + 1) * (x - 7) = 0 <=>

<=> x + 1 = 0 and x - 7 = 0 <=>

<=> x = -1 and x = 7, x ∈ { 6; +∞ } <=>

<=> x = 7

Good luck! :)

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