Question

Please show steps in the calculation.

State whether each of the bolded numbers is the value of a parameter or the value of a statistic. Explain briefly.

1. A market research company is having a database that consists of all phone numbers in a certain city. One of the workers conducts market research by phone using his supervisor’s list of a sample of 500 phone numbers and found out 24% of the telephone numbers are outdated. This is not surprising because 26% of the phone numbers in the database are outdated.

2. A carload lot of bearings have a mean diameter of 2.51 cm and this is the specifications for acceptance of the lot by the purchaser. By chance, an inspector has chosen 100 bearings from the lot that found they have mean diameter=2.55 cm. Because this was outside the specified limits, the lot was rejected.

Answer 1

Ans:

We know that the statistical constant of a population is called parameter while the statistical value computed from a sample is called statistic.

a) Since we found out about 24% from a sample of 500 phone numbers so it is a statistic and 26% is the fact from population so it is a parameter

Statistic = 24%

Parameter = 26%

b) 2.55cm is obtained from a sample of 100 bearings so it is a statictic. 2.51 whereas is the fact derived from all the bearings so it is a parameter

Statistic = 2.55 cm

Parameter = 2.51 cm