The mean length of time required to earn bachelor's degree for a sample of 80 students is 4.8 years. Assuming that the population standard deviation is 2.2 years, contrsuct a 95% confidence intervak estimate of the population mean.
Heres what I did:
n=80
x=4.8
standard deviation=2.2
confidence interval=95%=0.95
alpha=0.05
alpha/2=.025=1.960
i used the formula:
X - Zalpha/2 * standard deviation over the sample # squared
< u < Zalpha/2 * standard deviation over the sample # squared + X
My answer: 4.32 years, 5.28 years
Heres what I did:
n=80
x=4.8
standard deviation=2.2
confidence interval=95%=0.95
alpha=0.05
alpha/2=.025=1.960
i used the formula:
X - Zalpha/2 * standard deviation over the sample # squared
< u < Zalpha/2 * standard deviation over the sample # squared + X
My answer: 4.32 years, 5.28 years