Ask question

Ask question

All categories

2 years ago

6

Among 420 randomly selected employees at a company, the mean number of hours of overtime worked per month is 10 hours and the st

andard deviation is 1. 6. What is the margin of error, assuming a 99% confidence level? 4. 12 0. 01 0. 20 20. 5.

2 answers:

kari74 [83]2 years ago

8 0

The margin of error of the random selection is 0.20

The given parameters are:

$n = 420$ --- the sample size

$\sigma = 1.6$ --- the standard deviation

$\bar x = 10$ --- the mean

$\alpha = 99\%$ --- the confidence level.

The margin of error (E) is calculated as follows:

$E = z \times \sqrt{\frac{\sigma^2}{n}}$

So, we have:

$E = z \times \sqrt{\frac{1.6^2}{420}}$

$E = z \times \sqrt{\frac{2.56}{420}}$

The z-value for 99% confidence level is 2.576.

Substitute 2.576 for z

$E = 2.576 \times \sqrt{\frac{2.56}{420}}$

$E = 2.576 \times \sqrt{0.006095}$

Take square roots

$E = 2.576 \times 0.0781$

Multiply

$E = 0.2012$

Approximate

$E = 0.20$

Hence, the margin of error is 0.20

Read more about margin of error at:

brainly.com/question/14396648

Fittoniya [83]2 years ago

7 0

Answer:

0.20

Step-by-step explanation:

You might be interested in

At a large Midwestern university, a simple random sample of 100 entering freshmen in 1993 found that 20 of the sampled freshmen

guajiro [1.7K]

Answer:

The 90% confidence interval for the difference of proportions is (0.01775,0.18225).

Step-by-step explanation:

Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem establishes 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 $s = \sqrt{\frac{p(1-p)}{n}}$

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

p1 -> 1993

20 out of 100, so:

$p_1 = \frac{20}{100} = 0.2$

$s_1 = \sqrt{\frac{0.2*0.8}{100}} = 0.04$

p2 -> 1997

10 out of 100, so:

$p_2 = \frac{10}{100} = 0.1$

$s_2 = \sqrt{\frac{0.1*0.9}{100}} = 0.03$

Distribution of p1 – p2:

$p = p_1 - p_2 = 0.2 - 0.1 = 0.1$

$s = \sqrt{s_1^2+s_2^2} = \sqrt{0.04^2 + 0.03^2} = 0.05$

Confidence interval:

$p \pm zs$

In which

z is the z-score that has a p-value of $1 - \frac{\alpha}{2}$ .

90% confidence level

So $\alpha = 0.1$ , z is the value of Z that has a p-value of $1 - \frac{0.1}{2} = 0.95$ , so $Z = 1.645$ .

The lower bound of the interval is:

$p - zs = 0.1 - 1.645*0.05 = 0.01775
$

The upper bound of the interval is:

$p + zs = 0.1 + 1.645*0.05 = 0.18225
$

The 90% confidence interval for the difference of proportions is (0.01775,0.18225).

6 0

3 years ago

(2/3 to the third power) what else equals the answer giving 88 points for it

antoniya [11.8K]

Step-by-step explanation:

please type the question correctly, it's confusing. thanks

3 0

3 years ago

What are the answers ?

Vadim26 [7]

Answer:

All of the answers if you consider the dashes both negative and positive, but if they are negative then its the last 3 only.

Step-by-step explanation:

5 0

2 years ago

I really need helppppp

Dmitry [639]

Answer: the distance of the boat from the foot of the lighthouse is 290.5 feet.

Step-by-step explanation:

The right angle triangle ABC representing the scenario is shown in the attached photo.

Angle A is alternate to the angle of depression, hence, they are the same.

The height of the lighthouse represents the opposite side of the right angle triangle. The distance, x of the boat from the foot of the lighthouse represents the adjacent side of the right angle triangle.

To determine x, we would apply

the tangent trigonometric ratio.

Tan θ, = opposite side/adjacent side. Therefore,

Tan 11.1 = 57/x

x = 57/Tan 11.1 = 57/0.1962

x = 290.5 feet to the nearest tenth.

6 0

3 years ago

What is the length of the diagonal of a rectangle whose width is 100 centimeters and whose length is 180 centimeters. ( round th

Aloiza [94]

D keep trying for your family

5 0

3 years ago

Read 2 more answers