Question

(1 point) For each situation, state the null and alternative hypotheses: (Type "mu" for the symbol μ , e.g. mu > 1 for the mean is greater than 1, mu < 1 for the mean is less than 1, mu not = 1 for the mean is not equal to 1. Please do not include units such as "mm" or "$" in your answer.) (a) The diameter of a spindle in a small motor is supposed to be 5.5 millimeters (mm) with a standard deviation of 0.15 mm. If the spindle is either too small or too large, the motor will not work properly. The manufacturer measures the diameter in a sample of 9 spindles to determine whether the mean diameter has moved away from the required measurement. Suppose the sample has an average diameter of 5.41 mm. H0 : Ha : (b) Harry thinks that prices in Caldwell are lower than the rest of the country. He reads that the nationwide average price of a certain brand of laundry detergent is $18.55 with standard deviation $0.70. He takes a sample from 4 local Caldwell stores and finds the average price for this same brand of detergent is $19.58. H0 : Ha :

Answer 1

(a)

H0 : mu = 5.5 against Ha : mu not = 5.5

(b)

H0 : mu >= 18.55 against Ha : mu < 18.55