What is the correct reason for statement 1

The salary of teachers in a particular school district is normally distributed with a mean of $50,000 and a standard deviation o

andrey2020 [161]

Answer:

D. 54,900

Step-by-step explanation:

We have been given that the salary of teachers in a particular school district is normally distributed with a mean of $50,000 and a standard deviation of $2,500.

To solve our given problem, we need to find the sample score using z-score formula and normal distribution table.

First of all, we will find z-score corresponding to probability $0.975(1-0.025)$ using normal distribution table.

From normal distribution table, we get z-score corresponding is $1.96$ .

Now, we will use z-score formula to find sample score as:

$z=\frac{x-\mu}{\sigma}$ , where,

$z$ = Z-score,

$z$ = Sample score,

$\mu$ = Mean,

$\sigma$ = Standard deviation

$1.96=\frac{x-50,000}{2,500}$

$1.96*2,500=\frac{x-50,000}{2,500}*2,500$

$4900=x-50,000$

$4900+50,000=x-50,000+50,000$

$54900=x$

Therefore, the salary of $54900 divides the teachers into one group that gets a raise and one that doesn't.

4 0

3 years ago

In 2008 the Better Business Bureau settled 75% of complaints they received (USA Today, March 2, 2009). Suppose you have been hir

Ede4ka [16]

Answer:

Explained below.

Step-by-step explanation:

According to the Central limit theorem, if from an unknown population large samples of sizes n > 30, are selected and the sample proportion for each sample is computed then the sampling distribution of sample proportion follows a Normal distribution.

The mean of this sampling distribution of sample proportion is:

$\mu_{\hat p}= p$

The standard deviation of this sampling distribution of sample proportion is:

$\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}$

(a)

The sample selected is of size <em>n</em> = 450 > 30.

Then according to the central limit theorem the sampling distribution of sample proportion is normally distributed.

The mean and standard deviation are:

$\mu_{\hat p}=p=0.75\\\\\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.75(1-0.75)}{450}}=0.0204$

So, the sampling distribution of sample proportion is $\hat p\sim N(0.75,0.0204^{2})$ .

(b)

Compute the probability that the sample proportion will be within 0.04 of the population proportion as follows:

$P(p-0.04$

$=P(-1.96$

Thus, the probability that the sample proportion will be within 0.04 of the population proportion is 0.95.

(c)

The sample selected is of size <em>n</em> = 200 > 30.

Then according to the central limit theorem the sampling distribution of sample proportion is normally distributed.

The mean and standard deviation are:

$\mu_{\hat p}=p=0.75\\\\\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.75(1-0.75)}{200}}=0.0306$

So, the sampling distribution of sample proportion is $\hat p\sim N(0.75,0.0306^{2})$ .

(d)

Compute the probability that the sample proportion will be within 0.04 of the population proportion as follows:

$P(p-0.04$

$=P(-1.31$

Thus, the probability that the sample proportion will be within 0.04 of the population proportion is 0.81.

(e)

The probability that the sample proportion will be within 0.04 of the population proportion if the sample size is 450 is 0.95.

And the probability that the sample proportion will be within 0.04 of the population proportion if the sample size is 200 is 0.81.

So, there is a gain in precision on increasing the sample size.

6 0

3 years ago

Captain has $30 flame has a $20 note $5 notes . how much more moneny does captain have

SCORPION-xisa [38]

Captain has $30 money

Flame has $20 +$5 =$25

difference =30-25=5

Captain has $5 more money

5 0

3 years ago

in 2005, the total waste generated in a certain country was 3.474x10^9 pounds. also in 2005, the countrys population was 1.23x10

Serggg [28]

Answer:

2824

Step-by-step explanation:

Take the number of pounds and divide by the number of people:

3.474×10⁹ / 1.23×10⁶

Divide the coefficients and subtract the exponents:

(3.474 / 1.23) × 10⁹⁻⁶

2.824×10³

So the country produced about 2,824 pounds of garbage per person in 2005.

7 0

3 years ago

The Better Baby Buggy Co. has just come out with a new model, the Turbo. The market research department predicts that the demand

dlinn [17]

Answer:

$68

Step-by-step explanation:

We have been given the demand equation for Turbos as $q=-4p+544$ , where q is the number of buggies the company can sell in a month if the price is $p per buggy.