# stats

A simple random sample of 30 items resulted in a sample mean of 15. The population standard deviation is σ = 8. Round your answers to two decimal places.

a. What is the standard error of the mean, σx?

b. At 95% confidence, what is the margin of error?

1. 👍
2. 👎
3. 👁

## Similar Questions

1. ### Math I need help ASAP!

1. which of the following is true of a random sample? a. it is the only way to sample a population. b. each member of the sample is a volunteer. c. it is always the easiest way to sample a population. d. each member of the

A random sample of size 15 taken from a normally distributed population reveled a sample mean of 75 and a sample variance of 25. The upper limit of a 95% confidence interval for the population mean would equal?

3. ### statistics

A simple random sample of 40 items resulted in a sample mean of 25. The population standard deviation is 5. a. What is the standard error of the mean (to 2 decimals)? b. At 95% confidence, what is the margin of error (to 2

4. ### statistics

Suppose a random sample of 36 is selected from a population with a standard deviation of 12. If the sample mean is 98, the 99% confidence interval to estimate the population mean is

1. ### statistics

A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is 15. a) Compute the 95 % confidence interval for the population mean. b) Assume that the same sample mean was obtained from a

2. ### algebra

A simple random sample is drawn from a normally distributed population. The value of which of the following will not be known for certain but can be inferred?

3. ### statistics

A simple random sample of 50 items from a population with σ  6 resulted in a sample mean of 32. a. Provide a 90% confidence interval for the population mean

4. ### statistics

The scores of students on the ACT college entrance examination in a recent year had a normal distribution with a mean of 18.6 and a standard deviation of 5.9. A simple random sample of 50 students who took the exam is selected for

1. ### Stats

A sample of 400 items is taken from a population whose standard deviation is 10. The mean of the sample is 40. Test whether the sample has come from a population with mean 38. Also calculate 95% confidence interval for the

2. ### Government

1) The portion of the population selected to participate in a poll is known as the a. public b. population c. deliberative group d. sample e. focus group 2) A sample that does not overrepresent any portion of the population and

3. ### stats

Three firms carry inventories that differ in size. Firm A's inventory contains 2000 items, firm B's inventory contains 5000 items, and firm C's inventory contains 10,000 items. The population standard deviation for the cost of the

4. ### Algebra 1

Can you please check my work? A city planning committee surveys 100 people waiting at a bus stop about the expansion of the public transportation system. Is this an example of a: random sample, systematic sample, self-selected