A bank is investigating ways to entice customers to charge more on their credit cards. (Banks earn a fee from the merchant on each purchase, and hope to collect interest from the customers, as well.) A bank selects a random group of customers who are told their "cash back" will increase from 1% to 2% for all charges above a certain dollar amount each month. Of the 500 customers who were told the increase applied to charges above $1000 each month, the average increase in spending was $527 with a standard deviation of $225. Of the 500 customers who were told the increase applied to charges above $2000 each month, the average increase in spending was $439 with a standard deviation of $189. A level C = 95% confidence interval for \mu_1\:-\:\mu_2μ 1 − μ 2 is approximated by Group of answer choices (62.2, 113.8) (86.2, 120.5) (10.3, 23.8) (55.6, 67.8)

Answers

Answer 1

Answer:

[tex]CI = (\bar{x_{1} } - \bar{x_{2}} ) \pm MoE\\\\[/tex]

[tex]CI = (527 - 439) \pm 25.75\\\\CI = 88 \pm 25.75\\\\CI = 88 - 25.75 \:\: and \:\: 88 + 25.75\\\\CI = (62.2 \: ,\: 113.8 )[/tex]

The correct answer choice is a. (62.2, 113.8)

Step-by-step explanation:

Of the 500 customers who were told the increase applied to charges above $1000 each month, the average increase in spending was $527 with a standard deviation of $225.

Sample size = n₁ = 500

Sample mean = x₁ = $527

Standard deviation = s₁ = $225

Of the 500 customers who were told the increase applied to charges above $2000 each month, the average increase in spending was $439 with a standard deviation of $189

Sample size = n₂ = 500

Sample mean = x₂ = $439

Standard deviation = s₂ = $189

We are asked to find the 95% confidence interval for the difference between two means.

The given group of answer choices are

a. (62.2, 113.8)

b. (86.2, 120.5)

c. (10.3, 23.8)

d. (55.6, 67.8)

The confidence interval for the difference between two means is given by

[tex]CI = (\bar{x_{1} } - \bar{x_{2}} ) \pm MoE\\\\[/tex]

Where [tex]\bar{x_{1} }[/tex] and [tex]\bar{x_{2} }[/tex] are the given sample means and margin of error is given by

[tex]$ MoE = z_{\alpha/2} \cdot \sqrt{\frac{s_{1}^2}{n_1} + \frac{s_{2}^2}{n_2}} $[/tex]

The z-score corresponding to 95% confidence level is given by

Significance level = α = 1 - 0.95 = 0.05/2 = 0.025

From the z-table at α = 0.025 the z-score is 1.96

[tex]$ MoE = 1.96 \cdot \sqrt{\frac{225^2}{500} + \frac{189^2}{500}} $[/tex]

[tex]MoE = 1.96 \cdot 13.14[/tex]

[tex]MoE = 25.75[/tex]

Finally,

[tex]CI = (\bar{x_{1} } - \bar{x_{2}} ) \pm MoE\\\\[/tex]

[tex]CI = (527 - 439) \pm 25.75\\\\CI = 88 \pm 25.75\\\\CI = 88 - 25.75 \:\: and \:\: 88 + 25.75\\\\CI = (62.2 \: ,\: 113.8 )[/tex]

Therefore, the correct answer choice is a. (62.2, 113.8)

How to use z-table?

In the z-table find the probability of 0.025

Note down the value of that row, it would be 1.9.

Note down the value of that column, it would be 0.06.

Add the two numbers together.

The z-score is 1.9 + 0.06 = 1.96


Related Questions

If ABC ~ DEF what is the scale factor of abc to def

Answers

Answer:

It might be 1/3 but I'm not 100% sure

The required scale factor  of ABC to DEF is 1/3.

Scale factor of ABC to DEF to determine.

What is scale factor?

The scale factor is defined as the ratio of modified change in length to

Here, Triangle ABC is similar to triangle DEF. So, the ratio of the same sides describe the scale factor.
Scale factor = EF/BC
                   = 7/21
                   = 1/3

Thus, the required scale factor  of ABC to DEF is 1/3.

Learn more about Scale factor Here:
https://brainly.com/question/22312172

#SPJ5

Maddie is packing moving boxes. She has one 3 cubic-foot box and one 6 cubic-foot box. How many cubic feet of clothing can she fit in the two boxes?

8 9 10 12

Answers

Answer:

She can fit 9 cubic feet of clothing in the two boxes.

Step-by-step explanation:

She can fit a total of 3 cubic feet of clothing in one box, and the other she can fit a total 6 cubic feet.

3 + 6 = 9

Answer:

9 cu ft.

Step-by-step explanation:

That is the sum of the capacities of the 2 boxes

=  3 + 6

= 9 cu ft.

Complete this expression using the distributive property
5(4 + 8) =
O (5 + 4)(5 + 8)
O 5(4) + 8
O 5(4) + 5(8)
O (5+4) + (5 + 8)

Answers

Answer:

5(4) + 5(8)

Step-by-step explanation:

Through destributive property, 5 is multiplied by both 4 and 8

Answer:

the person above is right thank and five star them

Step-by-step explanation:

Help help , Please help! Brainliest if correct! What was the equation of the graph below before it was shifted to the left 1.5 units? A. G(x)=(x3)^3-(x-3) B. G(x)=(x-1.5)^3 C. G(x)=(x)^3 D.G(x)=x^3-x

Answers

Answer:

  A.  G(x) = (x -3)^3 -(x -3)

Step-by-step explanation:

The graph before it was shifted left will be a right-shift of the equation shown. That is accomplished by replacing x with (x-1.5). Then the right-shifted equation is ...

  G(x) = ((x-1.5) -1.5)^3 -((x -1.5) -1.5)

  G(x) = (x -3)^3 -(x -3) . . . . matches choice A

Classify the following triangle .check all that apply

Answers

Answer:

acute and scalene

Step-by-step explanation:

Answer:no entiendo esta en ingles

Step-by-step explanation:

Express each percent as a fraction in simplest form.
a. 85%
b. 5 72%
c. 12.55%​

Answers

Answer:

(a) 17/20 b.5/18/25 c. 1.255

Find the equation of a line perpendicular to 2x-4y=1 that contains the point (-4, -2).

Answers

Answer:

y = -2x - 10

Step-by-step explanation:

1. rearrange to find the gradient.

the gradient of the original equation is 1/2 hence why a line PERPENDICULAR to that equation would have a gradient of -2.

2. substitute into y - y1 = m (x - x1)

y - (-2) = -2 (x - (-4))

y = -2x - 10

An amount was invested at r% per quarter. What value of r will ensure that accumulated amount at the end of one year is 1.5 times more than amount invested? Correct to 2 decimal places

Answers

Answer:

25.75 %  interest rate

Step-by-step explanation:

Given:

Amount was invested = r% per quarter  

Amount invested = P

Rate of interest = r %  per quarter

Time (n) = 4  Quarters

Computation:

A = P(1 + r/100)ⁿ

According to question.

⇒ A = P + 1.5P  = 2.5P

⇒ 2.5P = P(1 + r/100)⁴

⇒ 2.5  = (1  + r/100)⁴

⇒ 1 + r/100  =  1.2575

⇒ r/100 = 0.2575

⇒ r = 25.75

25.75 %  interest rate

The mean weight of frozen yogurt cups in an ice cream parlor is 8 oz.Suppose the weight of each cup served is normally distributed withstandard deviation 0.5 oz, independently of others.(a) What is the probability of getting a cup weighing more than 8.64oz

Answers

Answer:

10.03% probability of getting a cup weighing more than 8.64oz

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

[tex]\mu = 8, \sigma = 0.5[/tex]

What is the probability of getting a cup weighing more than 8.64oz

This is the 1 subtracted by the pvalue of Z when X = 8.64. So

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

[tex]Z = \frac{8.64 - 8}{0.5}[/tex]

[tex]Z = 1.28[/tex]

[tex]Z = 1.28[/tex] has a pvalue of 0.8997

1 - 0.8997 = 0.1003

10.03% probability of getting a cup weighing more than 8.64oz

6
Cheryl had 160 stickers more than Gareth. If Cheryl gave 185 stickers
to Gareth, Gareth would have 3 times as many stickers as Cheryl
How many stickers did Gareth have at first?
165​

Answers

Answer:

260 stickers

Step-by-step explanation:

Let Gareth's stickers be x.

Hence Cheryl sticker is 160+x;

If Cheryl gave 185 stickers

to Gareth, it means:

Cheryl has at the moment;

160 + x - 185 = x - 25

At this time when Gareth receives 185 he now has:

x+ 185

Also when he receives x +185, he has 3 times Cherry's meaning:

x+185 =3(x-25)

x + 185 = 3x -75

185 + 75 = 3x-2x

260= x

x = 260.

Hence Gareth has 260 stickers

According to the February 2008 Federal Trade Commission report on consumer fraud and identity theft, 23% of all complaints in 2007 were for identity theft. In that year, Alaska had 321 complaints of identity theft out of 1,432 consumer complaints (Consumer fraud and, 2008). (7.1.2)

State the random variable, population parameter, and hypotheses.

Answers

Answer:

Random variable: for this case represent the number of complaints in 2007

Population parameter: represent the real proportion of complaints in 2007 p

Hypothesis to verify

We want to check if the true proportion of complaints in 2007 is equal to 0.23, the system of hypothesis are.:  

Null hypothesis:[tex]p=0.23[/tex]  

Alternative hypothesis:[tex]p \neq 0.23[/tex]  

Step-by-step explanation:

Information provided

n=1432 represent the random sample taken

X=321 represent the number of complaints

[tex]\hat p=\frac{321}{1432}=0.224[/tex] estimated proportion of complaints in 2007

[tex]p_o=0.23[/tex] is the value to verify

z would represent the statistic

Random variable: for this case represent the number of complaints in 2007

Population parameter: represent the real proportion of complaints in 2007 p

Hypothesis to verify

We want to check if the true proportion of complaints in 2007 is equal to 0.23, the system of hypothesis are.:  

Null hypothesis:[tex]p=0.23[/tex]  

Alternative hypothesis:[tex]p \neq 0.23[/tex]  

someone plz help asap plz

Answers

Answer:

a) 6

b) 10

Step-by-step explanation:

a) The area of a rhombus is half the product of the diagonals, meaning that the area of the shaded part is 4*3/2=6 square meters.

b) To find the area of the white background, you need to find the area of the full rectangle, and then to find the area of both rhombii. The area of the black rhombus is 2*4/2=4 square meters. The area of the full rectangle is 4*5=20 units. Subtracting the areas of the two rhombii, you get an area for the white background of 20-6-4=10 square meters. Hope this helps!

3. Set up an equation and use it to solve for x.
51°
(5x + 1)

Answers

Answer:

51 = 5x+1

x = 10

Step-by-step explanation:

The angles are vertical angles which means they are equal

51 = 5x+1

Subtract 1 from each side

51-1 = 5x+1-1

50 = 5x

Divide each side by 5

50/5 = 5x/5

10 =x

Answer:

10

Step-by-step explanation:

51 = 5x + 1

5x = 51 - 1

5x = 50

x = 10

Hope this helps!

What is the value of expression below? 7/2-4.5x3+8

Answers

Answer:-2

Step-by-step explanation:

Ok so I’m assuming the x stands for the multiplication sign

7/2-4.5*3+8

Use pemdas

Multiplication first

7/2-4.5*3+8

-4.5*3

7/2-13.5+8

Then addition

-13.5+8

Lastly subtraction

7/2-5

-2

Express loga 6 + loga 70 as a single logarithm

Answers

Answer:

logₐ(420)

Step-by-step explanation:

Answer:

The answer is

[tex] log_{a}(420) [/tex]

Step-by-step explanation:

You have to use Logarithm Law,

[tex] log_{a}(b) + log_{a}(c) ⇒ log_{a}(b \times c) [/tex]

* Take note, number b and c can only be multiplied when they have the same base, a

So for this question :

[tex] log_{a}(6) + log_{a}(70) [/tex]

[tex] = log_{a}(6 \times 70) [/tex]

[tex] = log_{a}(420) [/tex]

A Biology test contains 10 multiple choice questions each with 5 choices and one correct answer. If a law school student just randomly guesses on each of the 10 questions, i.e., the probability of getting a correct answer on any given question is 0.2. Assume that all questions are answered independently. (a) What is the probability that the student answers at least 9 questions correctly

Answers

Answer:

0.0004% probability that the student answers at least 9 questions correctly

Step-by-step explanation:

For each question, there are only two possible outcomes. Either the student guesses the correct answer, or he does not. All questions are answered independently. This means that we use the binomial distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

In this question, we have that:

[tex]n = 10, p = 0.2[/tex]

What is the probability that the student answers at least 9 questions correctly

[tex]P(X \geq 9) = P(X = 9) + P(X = 10)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 9) = C_{10,9}.(0.2)^{9}.(0.8)^{1} = 0.000004[/tex]

[tex]P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} \approx 0 [/tex]

[tex]P(X \geq 9) = P(X = 9) + P(X = 10) = 0.000004 + 0 = 0.000004[/tex]

0.0004% probability that the student answers at least 9 questions correctly

What’s the correct answer for this question?

Answers

Answer:

A.

Step-by-step explanation:

Volume of sphere = (4/3)πr³

= 4/3(3.14)(d/2)³

= 4/3(3.14)(7/2)³

= 4/3(3.14)(3.5)³

= 4/3(3.14)(42.875)

= (1.33)(3.14)(42.875)

= 179.5 cm³

Answer:

The answer is 179.5 cm^2

Please answer this correctly

Answers

Answer:

4

Step-by-step explanation:

Set the height of the missing bar to 4 as there are 4 quantities between 21-25.

The commute would be 4, because in the number bank there’s 2 #21’s and 2 #23’s and 2+2=4

Write the value of the digit 5 in this number:178.25
I​

Answers

Step-by-step explanation:

178.25

The number 5 is in the place of one's so the value of 5 is 5

(TEKS 2A.) EF has endpoints E (8,3) and F(-4,9). What is the distance of the given segment?
A 8.544
C 11.250
B 10.345
D 13.416

Answers


Maybe D, I’m learning this same subject
I think it’s the answer is B

how to differentiate functions​

Answers

Answer:  see boxed answers below

Step-by-step explanation:

(i) multiply the exponent to the coefficient then subtract 1 from the exponent.

[tex]y=\dfrac{3}{5x^3}+3x^4+2x^2-20\\\\\\\text{rewrite it as follows}: y=\dfrac{3}{5}x^{-3}+3x^4+2x^2-20x^0\\\\\\y'=(-3)\dfrac{3}{5}x^{-3-1}+(4)3x^{4-1}+(2)2x^{2-1}-(0)20x^{0-1}\\\\\\y'=-\dfrac{9}{5}x^{-4}+12x^3+4x^1-0\\\\\\y'=\large\boxed{-\dfrac{9}{5x^{4}}+12x^3+4x}[/tex]

(ii) Use the division formula:    [tex]y = \dfrac{a}{b}\rightarrow \quad y'=\dfrac{ab'-a'b}{b^2}[/tex]

[tex]a=5x^3+1\qquad \qquad a'=15x^2\\b=3x^5+4x^2\qquad \quad b'=15x^4+8x\\\\\\y'=\dfrac{(15x^2)(3x^5+4x^2)-(5x^3+1)(15x^4+8x)}{(3x^5+4x^2)^2}\\\\\\.\quad =\dfrac{45x^7+60x^4-75x^7-55x^4-8x}{(3x^5+4x^2)^2}\\\\\\.\quad =\large\boxed{\dfrac{-35x^7+5x^4-8x}{(3x^5+4x^2)^2}}[/tex]

A standardized​ exam's scores are normally distributed. In a recent​ year, the mean test score was 1521 and the standard deviation was 314. The test scores of four students selected at random are 1920​, 1290​, 2220​, and 1420. Find the​ z-scores that correspond to each value and determine whether any of the values are unusual

Answers

Answer:

A score of 1920 has a z-score of 1.27.

A score of 1290 has a z-score of -0.74.

A score of 2220 has a z-score of 2.23.

A score of 1420 has a z-score of -0.32.

The score of 2220 is more than two standard deviations from the mean, so it is unusual.

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

If X is 2 or more standard deviations from the mean, it is considered unusual.

In this question, we have that:

[tex]\mu = 1521, \sigma = 314[/tex]

Score of 1920:

X = 1920. Then

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

[tex]Z = \frac{1920 - 1521}{314}[/tex]

[tex]Z = 1.27[/tex]

A score of 1920 has a z-score of 1.27.

Score of 1290:

X = 1290. Then

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

[tex]Z = \frac{1290 - 1521}{314}[/tex]

[tex]Z = -0.74[/tex]

A score of 1290 has a z-score of -0.74.

Score of 2220:

X = 1290. Then

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

[tex]Z = \frac{2220 - 1521}{314}[/tex]

[tex]Z = 2.23[/tex]

A score of 2220 has a z-score of 2.23.

Since it is more than 2 standard deviations of the mean, the score of 2220 is unusual.

Score of 1420:

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

[tex]Z = \frac{1420 - 1521}{314}[/tex]

[tex]Z = -0.32[/tex]

A score of 1420 has a z-score of -0.32.

A box lunch costs b. A bag of chips is $2 extra. Choose the expression to show the cost of 12 lunches with chips and 10 lunches without?

Answers

Answer:

22b+24

Step-by-step explanation:

If a box lunch costs b and a bag of chips is $2 extra then we would have:

box lunch = b dollars

box lunch with bag of chips = b + 2 dollars

Now, we need to find the expression for the cost of 12 lunches with chips and 10 lunches without chips, this would be:

12 lunches with chips = 12 (b + 2)

10 lunches without chips = 10b

Let's sum up and simplify these two expressions:

[tex]12(b+2)+10b\\12b+24+10b\\22b+24[/tex]

Thus, the cost of 12 lunches with chips and 10 lunches without chips is 22b+24

8. Mr. Azu invested an amount at rate of 12% per annum and invested another amount, GH¢
580.00 more than the first at 14%. If Mr. Azu had total accumulated amount of
GH¢2,358.60, how much was his total investment?

Answers

Answer:

GH¢. 18098.46

Step-by-step explanation:

Let the first investment giving 12% interest per annum be Bank A

Let the 2nd investment giving 10% per annum be bank B

Let the first amount invested be

GH¢. X and let the second amount invested be GH¢. X + 580

Thus; In bank A;

Principal amount in first = GH¢. x

rate = 12 %

time = 1 year

Formula for simple interest = PRT/100

Where P is principal, R is rate and T is time.

So, interest in his investment = 12X/100 = 0.12X

while in bank B;

principal amount = GH¢. X + 580

rate = 14%

time = 1 yr

So, interest in his investment = [(X + 580) × 14]/100

= 0.14(X + 580)

So, total accumulated interest is;

0.12X + 0.14(X + 580) = 0.12X + 0.14X + 81.2 = 0.26X + 81.2

Now, we are given accumulated interest = GH¢. 2,358.60

Thus;

2358.60 = (0.26X + 81.2)

2358.6 - 81.2 = 0.26X

X = 2277.4/0.26

X = 8759.23

So,

first amount invested = GH¢. 8759.23

Second amount invested = GH¢. 8759.23 + GH¢. 580 = GH¢. 9339.23

Total amount invested = GH¢. 8759.23 + GH¢. 9339.23 = GH¢. 18098.46

Rewrite the expression in the form z^n
[tex] \sqrt[5]{z {}^{4}z {{}^{ \frac{ - 3}{2} } } } [/tex]

Answers

Answer:

[tex]z^{0.5}[/tex]

Step-by-step explanation:

So first simplify inside:

[tex]z^4z^{-1.5}=z^{2.5}[/tex]

Now divide that by 5:

[tex]z^{0.5}[/tex]

* If you are given the measurements of two sides of a triangle,
what will be true about the triangles you make?

Answers

They are congruent

Explanation: We can prove triangles are congruent by sssif

Answer:both sides will be equal

Step-by-step explanation:

What is the value of x to the nearest tenth? gradpoint

Answers

Answer:

5

Step-by-step explanation:

A local cable company claims that the proportion of people who have Internet access is less than 63%. To test this claim, a random sample of 800 people is taken and its determined that 478 people have Internet access. The following is the setup for this hypothesis test: H0:p=0.63 Ha:p<0.63 Find the p-value for this hypothesis test for a proportion and round your answer to 3 decimal places.

Answers

Answer:

Step-by-step explanation:

For the null hypothesis,

H0 : p = 0.63

For the alternative hypothesis,

Ha : p < 0.63

This is a left tailed test

Considering the population proportion, probability of success, p = 0.63

q = probability of failure = 1 - p

q = 1 - 0.63 = 0.37

Considering the sample,

Sample proportion, P = x/n

Where

x = number of success = 478

n = number of samples = 800

P = 478/800 = 0.6

We would determine the test statistic which is the z score

z = (P - p)/√pq/n

z = (0.6 - 0.63)/√(0.63 × 0.37)/800 = - 1.76

From the normal distribution table, the area below the test z score in the left tail 0.039

Thus

p = 0.039

Answer:

-3.66

Step-by-step explanation:

Find the length of Line segment A C . Use that length to find the length of Line segment C D . Triangle A B C is shown. A perpendicular bisector is drawn from point A to point C on side B D. Angle A B C is 30 degrees and angle A D C is 25 degrees. The length of A B is 10 centimeters. What is the length of Line segment C D? Round to the nearest tenth. 2.3 cm 4.0 cm 10.7 cm 18.6 cm

Answers

Answer:

10.7 CM

Step-by-step explanation:

Correct on Edge 2020

Answer:

answer is C  10.7 cm

Step-by-step explanation:

got it right on edg 2020-2021

y = -9x - 2; (4, -37)

A. Yes it satisfies the equation
B. No the ordered pair does not satisfy the equation

Answers

Answer:

B. No the ordered pair does not satisfy the equation

Step-by-step explanation:

y = -9x - 2

Substitute the point in and see if it is true

-37 = -9(4) -2

-37 = -36 -2

-37 = -38

This is not true so the point is not a solution

Other Questions
HELP PLEASE How do laws and regulations help promote competition? Describe how the political climate changed in Italy, Germany and Japan that set off World War II. Which word means the condition of being ready? Simplify the radical expression.- V8n2 12 What are the factors of this quadratic function? Find the total amount owed, to the nearest cent, for a simple interest loan with a principal of $2950, an interest rate of 7.4% and a time period of 1.5 years. Show Which of the following statements best describes adjacent angles?Adjacent angles are vertical.O Adjacent angles are supplementary.Adjacent angles share interior points.Adjacent angles share a side. The extract of which gymnosperm seed is used to help improve memory? What equation represents three less than 1/5 of a number is 28 if the sum of two ratinol numbers is 30 and there ratio is 2:3 then find the numbers please help me with this A recent article1 claims that "Green Spaces Make Kids Smarter." The study described in the article involved 2623 schoolchildren in Barcelona. The researchers measured the amount of greenery around the children's schools, and then measured the children's working memories and attention spans. The children who had more vegetation around their schools did better on the memory and attention tests. (a) What are the cases in this study? (b) What is the explanatory variable? (c) What is the response variable? (d) Does the headline imply causation? (e) Is the study an experiment or an observational study? (f) Is it appropriate to conclude causation in this case? a introduction paragraph about coal and natural gas 2. Which sentences expresses the idea most precisely and concisely?A. The Consuls decision he made alone was life altering for many people.B. The Consuls decision, made alone, altered the lives of many people.C. The Consuls decision, being made alone, altered the lives of many people.D. The decision of the Consul, made by him alone, altered the lives of many people. So how you liking Earth? Are you loving your existence ? A rocket rises vertically, from rest, with an acceleration of 3.99 m/s2 until it runs out of fuel at an altitude of 775 m. After this point, its acceleration is due to gravity downwards. What is the speed of the rocket, in m/s, when it runs out of fuel? A circular Petri dish has a diameter of 10 centimeters. If the dish contains 2.450 bacteria, what is thepopulation density of bacteria in the dish?(1) 31 bacteria per square centimeter(2) 42 bacteria per squarecentimeter(3) 48 bacteria per square centimeter(4) 51 bacteria per square centimeter Find an equation for the line that passes through the points (2, 3) and (-6,5).Please I need help George is reading a book. At the end of 3 hours he has read 90 pages, and at the end of 5hours he has read 238 pages. What is the average rate of change? Type your numericalanswer below. Simplify 2x + x. What is the answer to this? What is 4.5 x 10 to the power of -6 in standard notation?