Point Estimate for the Population Proportion

Presented by Group 4

Point estimate: A single numberInterval estimate: Interval of numbers • A point estimate predicts a

parameter by a single number. An interval estimate is an interval of numbers that are believable values for the parameter.

Lesson Objectives • Understand the population proportion • Illustrate the sampling distribution

estimator of • State the characteristics of the sampling

distribution of the estimator of • Identify the point estimator for the

population proportion • Compute the point estimator of a

population proportion

Point Estimate • Proportions can be obtained from

samples or populations.• To facilitate our discussions you

should use the following symbols. = number of observations in a simple random sample = sample proportion ( read as “p hat”) = population proportion =

Point Estimate • = population proportion

sample proportion of x successes in a sample of size n . Unbiased estimate (best estimate) = 1 - = sample proportion of failures in a sample size n

Example #1 • Find the point estimate of the proportion of

people wear hearing aids , if a random sample of 200 people , 25 people had hearing aids.

Example #2• In a political rally an opinion poll was

conducted among the present voters if they approve the platform of the candidate. 201 said they do approve. If there were 500 individuals in the sample what is p ? What is q?

Characteristics of Sampling Distribution of

Get a partner and answer the given

exercise in 1 whole sheet of paper