Show steps in the calculation. make sure you include checking conditions for using the clt.
the human resources (hr) department of a certain college has asked all employees who were employed in 2018 to fill out a survey in december 2018. three items on the survey were: “your dental expense in 2018”, “are you in a family with at least three other family members? ”, and “your medical expenses in 2018”. the manager of hr has randomly selected a sample of 169 surveys. found that the sample average dental expense is $1600 per person with the sample standard deviation is $500. 70 of them are in a family of at least three other members. also, the sample average medical expense is $2,450 per person and the sample standard deviation is $700.
the statistical inference will be made in parts (b), (c) and (d). clearly state the three parameters of interest.
provide a 99% interval estimate of the average dental expenses per employee who was employed in the year 2018. interpret your answer.
using a 95% confidence interval, estimate the proportion of all employees who were employed in the year 2018 are in a family of at least three members. interpret your answer.
as stated, the sample average medical expenses were $2,450. with your knowledge, the actual average price is more than $2,350. obviously, 2,450 is more than 2,350 but this is only from a sample and is only $100 more, does it really mean that the actual average medical expenses are more than $2,350? conduct a hypothesis test to prove the actual average medical expenses is more than $2,350 with a 5% level of significance. use p-value to do a conclusion. interpret your answer.