Exercise 4. Determining the Sample Size and Units in the Sample

Test 1: Instructions: Read each problem carefully. Use the appropriate formula and show your step-by-step solution to in solving the given problems.

1. Potential advertisers value television's well-known Nielsen ratings as a barometer of a TV show's popularity among viewers. The Nielsen rating of a certain TV program is an estimate of the proportion of viewers, expressed as a percentage, who watch the program on a given night. How large a sample is needed if we wish to be 90% confident that our estimate of the true proportion is correct within + 0.01?
2. A researcher wants a sample size of 230 to be drawn from a population which is divided into strata of size N1= 4 800, N2 = 7 000 and N3 = 3 200. Determine the sample size for the different strata by adopting proportional allocation.
3. A population is divided into three strata so that N1 = 10 000, N2 = 4 000 and N3 = 6 000. Respective standard deviations are 1 = 5, 2 = 10 and 3 = 20. How should a sample size of n = 1 020 be allocated to the three strata if the researcher opted for optimum allocation.
4. A researcher aims to determine the health status of the senior citizen in a certain municipality. The municipality has 60 barangays with a total of 9 108 senior citizens in the population.

A.Determine the 2^nd, 4^th and 7^th units in the sample using the table of random numbers given below.

2573769019

9235745106

0863571450

7043824098

4310671362

B.The researcher wants to use systematic sampling and a sample size of 320. Determine the following:

1)Sampling interval

2)The first three units in the sample if the random start is 2.

3)The middlemost unit/s if the random start is 5.

4)The last two units in the sample if the random start is 3.

Test 2: Instructions: Identify the sampling scheme applied in each of the given situations. Write the complete name of sampling procedure on the space provided for. Explain your answer in at most 5 (five) sentences.

1.Your classmates who are available during the survey will be taken as the sample for your study on the opinion of students in your school regarding the new enrolment system.What is the sampling? Explain your answer.

2.A survey obtained s sample of laborers by first classifying the different areas as either rural or urban. After which, a sample of laborers was taken from each area. What is the sampling? Explain your answer.

3.Twenty respondents from a certain company are formed. The 5^th, 10^th, 15^th , ... employee in the alphabetical listing of employees will be interviewed to determine their levels of satisfaction with the company's new biometric system. What is the sampling? Explain your answer.

4.One hundred children chosen at random by lottery method from the list of pupils enrolled in the barangay Day Care Center will form a sample for the study of occurrence of malnutrition among pre-school children in a certain barangay. What is the sampling? Explain your answer.

5.Students are grouped according to year level. Ten representative from each year level were chosen at random using lottery method to answer a survey on the use of Blended Learning Approach. What is the sampling? Explain your answer.