Q1) In random sample of 46 bolts, mean length was 1.28 inches and standard deviation was 0.07 inch. Use normal distribution or a t- distribution to create a 99% confidence interval for the mean.

Which distribution must be used to create the 99% confidence interval ?

a) Use normal distribution as the lengths are normally distributed and σ is known.

b) Use t-distribution because n≥ 30.

c) Use t- distribution as lengths are normally distributed and σ is known

d) Use normal distribution because n≥ 30.

e) 99% confidence interval is?

Q2) Using given data table, determine class interval for the wage table?

a) $4

b) $10

c) $14

d) $20

Q3) Using  given data table, find out midpoint for class with greatest frequency?

a) $4

b) $10

c) $14

d) $20