Question

7.0% of the U.S. population has O- blood type. In a sample of 500 individuals from the U.S., it is found that 5.8% have Type O- blood type.

a. In this scenario, is the value 7.0% a parameter or a statistic?

b. In this scenario, is the value 5.8% a parameter or a statistic?

Out of 500 people of interest, 30% have blonde hair. 25 people are selected for a sample and 20% of those are found to have blonde hair.

c. In this scenario, is the value 30% a parameter or a statistic?

d. In this scenario, is the value 20% a parameter or a statistic?

Answer 1

Let us first understand difference between parameter and statistics

Parameters are numbers that summarize data for an entire population. Statistics are numbers that summarize data from a sample, i.e. some subset of the entire population.

1. Based on the above definition we find that

a. 7.0% is the U.S. population who blood group is O-

Hence 7.0% is a parameter.

b. Now 5.8% is based on the sample hence it is statistics.

2. Here population size is 500 and sample size is 25.

a. As 30% is based on the population it is parameter

b. As 20% is based on the sample it is statistics.