Q1) Determine critical value t_c for confidence level c= 0.80 an dsample size n=11

Q2) In random sample of 23 people, mean number of books they had read in past year was 11.93 books and standard deviation was 16.60 books. Suppose variable is normally distributed and use a t- distribution to create a 80% confidence interval for population mean µ. What is the margin of error of µ .

Confidence interval for population mean µ is?

Q3) Perfectly balanced coin is tossed 6 times and tails appears on all six tosses. Then, on seventh trial

i) Tails can not appear 

ii) Heads has a larger chance of appearing than tails 

iii) Tails has a better chance of appearing than heads 

iv) None of these alternatives is correct.

Q4) Method of assigning probabilities based on historical data is known the

i) Classical method 

ii) Subjective method 

iii) Relative frequency method 

iv) Historical method