A researcher has gathered information from a random sample of 178 households. For each variable below, construct confidence intervals to estimate the population mean. Use the 90% level.
a. An average of 2.3 people resides in each household. Standard deviation is .35.
b. There was an average of 2.1 television sets (s 5 .10) and .78 telephones (s 5 .55) per household.
c. The households averaged 6.0 hours of television viewing per day (s 5 3.0).