= Test: Chapter 1-4 Test

What is the measure of angle B in degrees?

Kamila [148]

Answer:

119°

Step-by-step explanation:

51+180-112= 119°

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8 0

2 years ago

Read 2 more answers

A college requires applicants to have an ACT score in the top 12% of all test scores. The ACT scores are normally distributed, w

DochEvi [55]

Answer:

a) The lowest test score that a student could get and still meet the colleges requirement is 27.0225.

b) 156 would be expected to have a test score that would meet the colleges requirement

c) The lowest score that would meet the colleges requirement would be decreased to 26.388.

Step-by-step explanation:

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

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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 problem, we have that:

$\mu = 21.5, \sigma = 4.7$

a. Find the lowest test score that a student could get and still meet the colleges requirement.

This is the value of X when Z has a pvalue of 1 - 0.12 = 0.88. So it is X when Z = 1.175.

$Z = \frac{X - \mu}{\sigma}$

$1.175 = \frac{X - 21.5}{4.7}$

$X - 21.5 = 1.175*4.7$

$X = 27.0225$

The lowest test score that a student could get and still meet the colleges requirement is 27.0225.

b. If 1300 students are randomly selected, how many would be expected to have a test score that would meet the colleges requirement?

Top 12%, so 12% of them.

0.12*1300 = 156

156 would be expected to have a test score that would meet the colleges requirement

c. How does the answer to part (a) change if the college decided to accept the top 15% of all test scores?

It would decrease to the value of X when Z has a pvalue of 1-0.15 = 0.85. So X when Z = 1.04.

$Z = \frac{X - \mu}{\sigma}$

$1.04 = \frac{X - 21.5}{4.7}$

$X - 21.5 = 1.04*4.7$

$X = 26.388$

The lowest score that would meet the colleges requirement would be decreased to 26.388.

6 0

3 years ago

Scientists researching the effect of dietary supplements such as multivitamins and supplements of folic acid, magnesium or zinc

yarga [219]

Answer: Null hypothesis : $H_0: p_1=p_2$

Alternative hypothesis : $H_a: p_1\neq p_2$

Step-by-step explanation:

Let $p_1$ be the proportion of women using supplements and $p_2$ be the proportion of women who did not to have died during that period .

Then the set of hypothesis for testing if the proportion of women elderly women who use dietary supplements is different than those who do not will be :-

Null hypothesis : $H_0: p_1=p_2$ [∵ it takes equality sign]

Alternative hypothesis : $H_a: p_1\neq p_2$ [∵ it takes ≠ sign to show difference]

6 0

2 years ago

The formula for finding the area of a circle is a equals pi r square. solve the formula for r.

Reika [66]

I hope this helps you

Area=pi.r^2

r^2=Area/pi

r= square root of Area/pi

5 0

3 years ago

X squared plus 8 squared equals 9<br> What is X?

BabaBlast [244]

Answer:

x = $i\sqrt{55} , -i\sqrt{55}$

Step-by-step explanation:

x^2 + 8^2 = 9

Simplify the 8^2

x^2 + 64 = 9

Subtract 64 from both sides

x^2 = -55

Take the square root from both sides

x = +/- $\sqrt{-55}$

Simplify

x = $i\sqrt{55} , -i\sqrt{55}$

Hope this helps!

4 0

2 years ago