Confidence Intervals Stu uppose you per semester. You collect 45 observations. d
ID: 1160264 • Letter: C
Question
Confidence Intervals Stu uppose you per semester. You collect 45 observations. deviation of 2.6 population mean number of classes an SVSU student takes ions, with a sample mean of 3.42 and a sample standard want to estimate the mean point estimate for the population mean? 22. What is is a 95% confidence interval estimate for the population mean? 23, write down an interpretation of your 95% confidence interval. 24. what is a 99% confidence interval estimate for the population mean? 25, suppose that you have 100 observations instead of 45, what is a 95% confidence interval estimate for the population mean?Explanation / Answer
Ans a)
Point Estimate for the population mean is Sampe Mean hene inour case point estimate of sample mean wil be 3.42
Ans b)
95% confiedance interval for population mean
for 95% confiedance interval z value is 1.96 then interval will be calculated by
(Sample mean-z*Sample standard deviation,Sample mean+z*Sample standard deviation)
(3.42-1.96*2.6/sqrt(45),3.42+1.96*2.6/sqrt(45))=(2.660,4.179)
Ans C)
We are 95% sure that according to this sample population mean resides in between 2.660 and 4.179
Ans D)
z(alpha/2)=z(0.495)=2.576
(3.42-2.576*2.6/sqrt(45),3.42+2.576*2.6/sqrt(45))=(2.421,4.412)
Ans E)
Now sample size is 100 then for 95% confiedance interval will be
( (3.42-1.96*2.6/sqrt(100),3.42+1.96*2.6/sqrt(100))=(2.75,4.089)