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3 years ago

5

If you are trying to conduct an experiment by taking a random sample of home owners, which of the groups below should NOT be inc

luded in your sample? Select all that apply. A) 2nd Graders B) Homeowners in your neighborhood C) Members of a homeowner association D) High school students

2 answers:

Archy [21]3 years ago

4 0

A and D as they dont “own” their homes.

Artemon [7]3 years ago

3 0

Answer:

A & D for sure. Probably B

Step-by-step explanation:

Students don't own their homes. Homeowners in your neighborhood might not meet the definition of Random.

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Use the metric table to help complete the statement. Metric Table kilo- hecto- deka- unit deci- centi- milli- 1,000 100 10 1 0.1

Tom [10]

Answer:

C

Step-by-step explanation:

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2 years ago

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A prison official wants to estimate the proportion of cases of recidivism. Examining the records of 250 convicts, the official d

son4ous [18]

Answer:

For this sample, the estimated standard error is of 0.0277

Step-by-step explanation:

Central Limit Theorem

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

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 $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}}$

Examining the records of 250 convicts, the official determines that there are 65 cases of recidivism.

This means that $n = 250, p = \frac{65}{250} = 0.26$

For this sample, the estimated standard error is

$s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.26*0.74}{250}} = 0.0277$

For this sample, the estimated standard error is of 0.0277

4 0

3 years ago

At a college the scores on the chemistry final exam are approximately normally distributed, with a mean of 75 and a standard dev

AysviL [449]

Answer:

b) Chemistry

Step-by-step explanation:

To compare both scored we need to standardize the scores using the following equation:

$\frac{x-m}{s}$

Where x is the score, m is the mean and s is the standard deviation. So, 82 on chemistry is equivalent to:

$\frac{82-75}{15}=0.4667$

Because the mean of the scores on the chemistry final exam is equal to 75 and the standard deviation is 15

At the same way, 80 on Calculus is equivalent to:

$\frac{80-83}{13} =-0.2308$

Because the mean of the scores on the calculus final exam is equal to 83 and the standard deviation is 13

Now, we can compare the values. So, taking into account that -0.2308 is lower than 0.4667, we can said that the student do better in Chemistry.

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3 years ago

(8) In 10 years, Maria will be 39 years old. Let m represent Maria's age today. Which

makvit [3.9K]

Answer:

(3)

Step-by-step explanation:

if Maria is 39 in 10 years and m is her age today then you would have to add 10 to m to get 39

m+10=39 years old

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3 years ago

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Find the circumference of the circle. Then, find the length of each bolded arc. Use appropriate notation

Vaselesa [24]

Answer:

$\text{1) }\\\text{Circumference: }24\pi \text{ m}},\\\text{Length of bolded arc: }18\pi \text{ m}\\\\\text{3)}\\\text{Circumference. }4\pi \text{ mi},\\\text{Length of bolded arc: } \frac{3\pi}{2}\text{ mi}$

Step-by-step explanation:

The circumference of a circle with radius $r$ is given by $C=2\pi r$ . The length of an arc is makes up part of this circumference, and is directly proportion to the central angle of the arc. Since there are 360 degrees in a circle, the length of an arc with central angle $\theta^{\circ}$ is equal to $2\pi r\cdot \frac{\theta}{360}$ .

Formulas at a glance:

Circumference of a circle with radius $r$ : $C=2\pi r$
Length of an arc with central angle $\theta^{\circ}$ : $\ell_{arc}=2\pi r\cdot \frac{\theta}{360}$

<u>Question 1:</u>

The radius of the circle is 12 m. Therefore, the circumference is:

$C=2\pi r,\\C=2(\pi)(12)=\boxed{24\pi\text{ m}}$

The measure of the central angle of the bolded arc is 270 degrees. Therefore, the measure of the bolded arc is equal to:

$\ell_{arc}=24\pi \cdot \frac{270}{360},\\\\\ell_{arc}=24\pi \cdot \frac{3}{4},\\\\\ell_{arc}=\boxed{18\pi\text{ m}}$

<u>Question 2:</u>

In the circle shown, the radius is marked as 2 miles. Substituting $r=2$ into our circumference formula, we get:

$C=2(\pi)(2),\\C=\boxed{4\pi\text{ mi}}$

The measure of the central angle of the bolded arc is 135 degrees. Its length must then be:

$\ell_{arc}=4\pi \cdot \frac{135}{360},\\\ell_{arc}=1.5\pi=\boxed{\frac{3\pi}{2}\text{ mi}}$

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3 years ago