Question

2) Sammy wants to know what percent of students at her high school have a driver's license. She surverys all students in her statistics class and finds that 72% of the students in her sample have a driver's license.

a) What type of sample did Sammy obtain ?

b) Explain why this sampling method is biases. Is 72% likely to be greater than or less than the percentage of all students have a driver's license?

c) Explain how sammy could avoid the bias described in part b .

Answer 1

(a)

Sammy obtained convenience sample.

(b)

This convenience sampling method is non-probability sampling that involves the sample being drawn from that part of the population which ismost accessible. Here instead oftaking sample from the entire high school, Sammy has got information from students of her statistics class. This method of sampling has selection bias because proper randomization is not achieved.

72% is likely to be greater or less than the percentage of all students have a driver's licence because this value depends on the entire high school.

(c)

Sammy could avoid the above bias by taking sample from entire high school adopting statistical sampling tecniques instead of restricting to her statistics class.