Pure-Bred Dogs Competing in Shows Must Often Meet Specific Height
Pure-bred dogs competing in shows must often meet specific height criteria to be within the breed standard.A new breed of dog,the pug-cock-a-poo,has been approved by a kennel club.To establish the breed standard,the organization of breeders has taken the height from a sample of 25 pug-cock-a-poos and found the sample mean to equal 14 inches.The variance of this sample is 2.25.a.Construct a 90% confidence interval for the population mean height of the pug-cock-a-poos.b.What assumption is necessary for constructing the aforementioned interval?
A sample of the weights of 35 babies is taken from the local hospital maternity ward.The point estimate for the mean weight of the babies is 110.2 ounces with a sample standard deviation of 23.4 ounces.Construct a 90% confidence interval for the population mean baby weight at this hospital.Interpret this interval.
The personnel department of a large corporation wants to estimate the family dental expenses of its employees to determine the feasibility of providing a dental insurance plan.A random sample of six employees reveals the following family dental expenses: $180,$260,$60,$40,$100,and $80.It is known that dental expenses follow a normal distribution.Construct a 90% confidence interval for the average family dental expenses for all employees of this corporation.
A job candidate with an offer from a prominent investment bank wanted to estimate how many hours she would have to work per week during her first year at the bank.She took a sample of six first-year analysts,asking how many hours they worked in the last week.Construct a 95% confidence interval with her results: 64,82,74,73,78,and 87 hours.