1. Assume that a sample is used to estimate a mu population mean. Use the confidence level and sample data to find the margin of error. Assume that the sample is a simple random sample and the population has a normal distribution. Round your answer to one decimal more than the standard deviation of the sample. 95% confidence, n = 21; sigma = 0.16

a.0.085

b.0.068

c.0.063

d.0.073

2.Resolve the problem. Round to the tenth unless indicated otherwise. The amount of rain in January in a certain city is normally distributed with an average of 4.3 inches and a standard deviation of 0.3 inches. Find the value of the quartile.

a.1.1

b.4.1

c.4.2

d.4.5

3.Resolve the problem. Round the point estimate to the nearest thousandth. 430 randomly selected bulbs were tested in a laboratory, 224 lasted more than 500 hours. Find a point estimate of the proportion of all light bulbs that last more than 500 hours.

a.0.521

b.0.519

c.0.479

d.0.343

4.Resolve the problem. The following confidence interval is obtained for a proportion of the population, p: (0.707, 0.745). Use these confidence interval limits to find the margin of error, E.

a.0.038

b.0.017

c.0.019

d.0.020

5.Resolve the problem. In a certain population, body weights are distributed normally with an average of 152 pounds and a standard deviation of 26 pounds. How many people should be recognized if we want to estimate the percentage of those who weigh more than 180 pounds? Suppose that 96% confidence is desired that the error is not greater than 4 percentage points.

a.658

b.317

c.501

d.232

6.Use the confidence level given and the sample data for the construction of a confidence interval for the mu population mean. Assume that the population has a normal distribution. Thirty students selected at random took the final calculation. If the mean of the sample was 83 and it deviates

a. 76.21

b.76.23

c. 76.93

d.78.81

7.In a normal distribution:

a. The median and the fashion are different

b. The average, the median and the fashion are the same

c. The mean and the standard deviation are the same

d. The mean is greater than the standard deviation

8. Say the percent of the area under the curve of the standard normal distribution in the range 2

a. 68%

b.95%

c. 3. 4%

d. 99%