An Oklahoma survey of 90 golfers was conducted to learn how golfers view their treatment at golf courses in Oklahoma. The survey found that 40 of the golfers were satisfied with the availability of tee times.

i. what is the margin of error for 95% confidence interval? (Given: z_/2= 1.96)

ii. what is the lower end point of the interval estimate?

iii. what is the upper end point of the interval estimate?

iv. what is the interval for 95% confidence level?

When estimating the mean of a normally distributed population in situations where the sample size is small and the population standard deviation is unknown, we uset-distribution.

a.As the degrees of freedom increase, the t distribution approaches the _____ distribution.

b.if sample size is 30, degree of freedom is ............

c.as the sample size increases, the spread (dispersion) of the t-distribution .......... (increases/decreases?)