29 packages are randomly selected from packages received by a parcel service. The sample has a mean weight of 20.5 pounds. Assume that o=2,4 pounds. What is the 95% confidence interval for the true mean weight, u, of all packages received by the parcel service? O 19.2 to 21.8 pounds O 19.4 to 21.6 pounds O 19.3 to 21.7 pounds O 19.6 to 21.4 pounds

Researchers studied the mean egg length (in millimeters) for a bird population. After taking a random sample of eggs, they obtained a 95% confidence interval of (45,60). What is the value of the margin of error? Choose the correct answer below. A. 15 mm B. 52.5 mm O c. 7.5 mm O D. 1.96

A local university administers a comprehensive examination to the candidates for B.S. degrees in Business Administration. Five examinations are selected at random and scored. The scores are shown below. Develop a 95% confidence interval estimate for the mean of the population. Assume the population is normally distributed. Grades 80 90 91 62 77 Select one: O a. 65.39 - 94.61 O b. 68.78 - 91.22 О с. O d. 67.52 - 92.48 69.48 - 90.52

The following is the number of hours of sleep obtained by eight college freshmen.  Use the data to find a 92% confidence interval for the true mean number of hours of sleep by college freshmen. ​​7.5​    8.0​   6.5​  24​  8.5​  6.5​  7.0​   7.5