Constructa90%confidenceintervalforthetruemean,?,ofapopulationwithanormal distribution if a random sample of size ? = 75 has a mean of ?̅ = 12.5 and standard deviation ? = 0.9

A bank manager wants to know the mean amount of mortgage paid per month by homeowners in an areaA random sample of 116 homeowners selected from this area showed that they pay an average of $15 per month for their mortgages. The population standard deviation of such mortgages is $207 Find a 97 % confidence interval for the mean amount of mortgage paid per month by all homeowners in this area.

The mean age when smokers first start is 13 years old with a population standard deviation of 1.8 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS-electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 35 smokers found that their mean starting age was 12.3 years old. Do the data support the- claim at the 5% significance level? What are the correct hypotheses? Ho: Select an answer e years H1: Select an answer e years Based on the hypotheses, find the following: Test Statistic z = (Round to 4 decimal places.) Critical Values = = (Round to 2 decimal places.) Based on the above we choose to Select an answer O that the mean age smokers The correct summary would be: Select an answer first start is different than 13.

What is the typical age of a person who renews his orher driver’s license online? From a random sample of660 driver’s license renewal transactions, the mean agewas 52.6 and the standard deviation was 6.4. Computethe 98% confidence interval estimate of the mean ageof online renewal users in this county.

We surveyed a random sample of 15 domestic violence victims in Columbus, GA. who used the 911. From the sample response time from calling to police arrival was 8.5 minutes on average with a standard deviation of 2.7 minutes. From the estimaiton of the population mean of the arrival time with a 99% confidence interval, what is the upper limit?