Homework Soursein a recent study of 42 eighth graders the mean number of h
in a recent study of 42 eighth graders , the mean number of hours per week that they watched television Was 19.6. assume the population standard deviation is 5.8 hours. find the 98% confidence interval for the population mean.
in a recent study of 42 eighth graders , the mean number of hours per week that they watched television Was 19.6. assume the population standard deviation is 5.8 hours. find the 98% confidence interval for the population mean.
in a recent study of 42 eighth graders , the mean number of hours per week that they watched television Was 19.6. assume the population standard deviation is 5.8 hours. find the 98% confidence interval for the population mean.
Solution
Note that
Lower Bound = X - z(alpha/2) * s / sqrt(n)
Upper Bound = X + z(alpha/2) * s / sqrt(n)
where
alpha/2 = (1 - confidence level)/2 = 0.01
X = sample mean = 19.6
z(alpha/2) = critical z for the confidence interval = 2.326347874
s = sample standard deviation = 5.8
n = sample size = 42
Thus,
Lower bound = 17.51801303
Upper bound = 21.68198697
Thus, the confidence interval is
( 17.51801303 , 21.68198697 ) [ANSWER]
