Question

Retired professional tennis players Martina Navratilova, Monica Seles, John McEnroe, and Jimmy Connors are all left-handed. Define the parameter of interest to be the proportion of all professional tennis players (current and retired) who are left-handed. Only 20% of the general population is left-handed, but researchers believe this percent is higher in the population of all professional tennis players. In a survey of 47 professional tennis players, seven are left-handed.

Match each vocabulary word with its corresponding description in this study.

Sample Size:

Observational Units:

Statistic:

Variable:

What is the correct alternative hypothesis in this study?

Write the null hypothesis in words, being careful to specify the population and the parameter of interest.

Answer 1

Sample Size: 47

Observational Units: Each one of the 47 professional tennis players

Statistic: The test statistic for one sample test of proportion is

= -0.8752

Variable: Proportion of left-handed tennis players in the population denoted by p

The correct alternative hypothesis is

Ha : p > 0.2

(In hypothesis testing the alternative hypothesis is the one that we want to test for as the researcher)

The null hypothesis would be

H0 : p = 0.2

In words, this would mean that the proportion of professional tennis players who are left-handed is no different than the proportion of left-handed people in the general population which is 0.2.