15 POINTS! RIGHT ANSWERS ONLY! PLEASE! Thank you, explanation is optional.

2. Type: Hv G H (3,4), (8,4) The length of GH is 3 units.

alexdok [17]

Answer:

5 units

Step-by-step explanation:

(3,4), (8,4)

Since the y coordinates do not change, we are only concerned with x

8-3 = 5

The length of GH is 5 units

3 0

4 years ago

Jason has $70 in a savings account that earns 5% interest, compounded annually.

kvv77 [185]

Answer:

$77.18

Step-by-step explanation:

A = total amount

P = principal

I = interest

A = P(1 + r/n)^n·t

A = 70(1+.05)²

A = 70(1.05)²

A = 77.175

I = A - P

5 0

3 years ago

Read 2 more answers

To test the effect of classical music on the brain, a study has been done. Twenty 6th grade students are randomly divided into t

Volgvan

Answer:

Step-by-step explanation:

Hello!

A study was conducted to test the effect of classical music on the brain. For this 20 6th grade students were randomly divided into two independent groups of 10, the same math test was given to these students. The first group listened to classical music for 20 min before taking the test. The second group took the test without listening to music.

Sample 1 (With music)

X₁: Score of a 6th grade student that heard 20 min classical music before taking the math test.

91 77 58 89 83 78 74 81 91 88

n₁= 10

X[bar]₁= 81

S₁= 10.11

Sample 2 (Without music)

X₂: Score of a 6th grade student that didn't hear classical music before taking the math test.

81 65 69 69 67 61 67 87 64 81

n₂= 10

X[bar]₂= 71.10

S₂= 8.70

Asuming both variables have a normal distribution and the population variances are unknown but equal, the statistic to use for both the CI and hypothesis tests is:

t= (X[bar]₁-X[bar]₂) - (μ₁ - μ₂) ~t $_{n_1+n_2-2}$

Sa $\sqrt{\frac{1}{n_1} + \frac{1}{n_2} }$

a) 95% for (μ₁ - μ₂)

(X[bar]₁-X[bar]₂) ± $t_{n_1+n_2-2; 1-\alpha /2}$ *Sa $\sqrt{\frac{1}{n_1} + \frac{1}{n_2} }$

$Sa^2= \frac{(n_1-1)S_1^2+(n_2-1)S_2^2)}{n_1+n_2-2}$

$Sa^2= \frac{9*102.22+9*75.66}{18}$

Sa²= 88.94

Sa= 9.4308 ≅ 9.43

$t_{n_1+n_2-2;1-\alpha /2} = t_{18; 0.975} = 2.101$

(81-71.10) ± 2.101*(9.43* $\sqrt{\frac{1}{10} + \frac{1}{10} }$ )

[1.04;18.76]

With a confidence level of 95% youd expect that the interval [1.04;18.76] will contain the difference between the population means of the test scores of the kids that listened to classic music and the kids that didn't listen to music before taking the math test.

b)

H₀: μ₁ ≤ μ₂

H₁: μ₁ > μ₂

α: 0.05

One-tailed test (right tail)

Critical value

$t_{n_1+n_2-2; 1 - \alpha } = t_{18; 0.95} = 1.734$

Rejection region t ≥ 1.734

t= (81-71.10) - 0 = 2.34

9.43* $\sqrt{\frac{1}{10} + \frac{1}{10} }$

The decision is to reject the null hypothesis.

c) You are asked to conduct the same test at a different levelm this means that only the significance level changes:

H₀: μ₁ ≤ μ₂

H₁: μ₁ > μ₂

α: 0.01

One-tailed test (right tail)

Critical value

$t_{n_1+n_2-2; 1 - \alpha } = t_{18; 0.99} = 2.552$

Rejection region t ≥ 2.552

t= (81-71.10) - 0 = 2.34

9.43* $\sqrt{\frac{1}{10} + \frac{1}{10} }$

The decision is to not reject the null hypothesis.

At a significance level of 5%, the decision is to reject the null hypothesis, which means that the population average of the test scores of 6th-grade children that listened to classical music before taking a math test is greater than the population average of the test scores of 6th graders that took the math test without listening to classical music.

But at 1% significance level, there is not enough evidence to reject the null hypothesis. At this level, the conclusion is that the average test score of 6th graders that listened to classical music before taking the math test is at most equal to the average test score of 6th graders that didn't listen to music before the test.

I hope it helps!

4 0

3 years ago

Suppose you are conducting a study to determine if women are better drivers than men. You send your survey to over 1000 students

julsineya [31]

Answer:

555.56

Step-by-step explanation:

Purpose of the study: To determine if women are better drivers than men.

Survey or Opinion population: 1,000

You are experimenting on 9 out of a thousand opinions.

5 of these opinions are that women are better drivers

4 of these opinions are that women are not better drivers

You want to know the sample (full sample size is 9) proportion for women as better drivers; using the large sample method. This method is also called the asymptotic method.

This involves approximating the desired statistic, with just a small fraction of the population; in this case, 9/1000.

This approximation will get more and more accurate as sample size increases and you know that a larger sample size gives a better representation and interpretation of the population preference!

So using ratio, the sample proportion for women as the better drivers is given by:

5/9 x 1000 = 555.56 opinions

8 0

3 years ago

The yard behind the Cindy’s house is rectangular in shape and has a perimeter of 72 feet. If the length l of the yard is 18 feet

PtichkaEL [24]

Let
L----------> the length of the yard
W--------> the width l of the yard

we know that
the perimeter is equal to
 $P=2*[W+L]$
$72=2*[W+L] \\ 36=W+L$ --------> equation 1
$L=W+18$ ------> equation 2
substitute equation 2 in equation 1
 $36=W+18+W \\ 36=2W+18 \\ W=(36-18)/2$
$W=9 ft$
$L=W+18 \\ L=9+18 \\ L=27 ft$

we know that
Area of the rectangular yard is equal to
 $A=L*W \\ A=27*9 \\ A=243 ft^{2}$

4 0

4 years ago

Read 2 more answers