Q6. A) t-distribution
n is too small to use central limit theoremQ7. a) 95 will include μ
Those 100 samples are using X_bar to compute, 95 out of 100 times will include μ and 100 out of 100 times will include X_bar. Also, probability that each interval contains μ is either 1 or 0.Q8. a) 99% confident
similar reasons as Q7.Q9. d) 9,because the sum of sample values must equal 59
The population mean is unknown, so the degree of freedom of standard deviation has to minus 1.Q10. a) Lengthening of the confidence interval
Losing degree of freedom increases the margin error, and thus, lengthens the confidence interval.