MATH 225N Week 1 Assignment Sampling Methods – Questions and Answers

Questions 1. Assume that 80 houses are present in the form of a grid consisting of 10 columns and 8 rows. If a loud speaker is placed just before the first row, which sampling method works the best to select a sample ...

Questions 1. Assume that 80 houses are present in the form of a grid consisting of 10 columns and 8 rows. If a loud speaker is placed just before the first row, which sampling method works the best to select a sample of houses if we want to get an estimate of the average loudness (measured in decibels) near all the 80 houses? Select the correct answer below: Simple Random Sampling Stratified Sampling using the rows of the houses as strata Cluster Sampling using the rows of the houses as clusters Convenience Sampling 2. Angela is studying the mean blood pressure of all students attending her college. She collects data from the 38 students in her statistics class. Which type of sampling is used? Select the correct answer below: Cluster sampling Stratified sampling Systematic sampling Convenience sampling 3. A town planner is interested in getting some demographic data about the households in the city. The city has four wards with the following numbers of households: ward A has 2,107, ward B has 903, ward C has 1,505, and ward D has 1,499. The budget for the project allows the planner to survey 100 households. She plans to use a stratified sampling method. What number of households should be chosen from ward B? Enter a whole number. 903/2107+903+1505+1499 = 903/6014 x 100 = 15 4. Donald is studying the eating habits of all students attending his school. He samples the population by dividing the students into groups by grade level and randomly selecting a proportionate number of students from each group. He then collects data from the sample. Which type of sampling is used? Select the correct answer below: Systematic sampling Convenience sampling Stratified sampling Cluster sampling 5. An executive for a large national restaurant chain with multiple locations in each of 513 counties wants to personally sample the cleanliness of the chain's restaurants throughout the country by visiting restaurants. The executive wants a good-quality sample but wants to minimize travel time and expenses. Which of the following sampling methods would be most appropriate? Select the correct answer below: Obtain a convenience sample by visiting the 100 restaurants that are closest to the executive's office. Obtain a systematic sample by selecting every 20th restaurant from a list that orders all restaurants by date of opening. Obtain a stratified sample by visiting 1 randomly selected restaurant in every county. Obtain a cluster sample by randomly selecting 20 counties and visiting every restaurant within those counties. 6. When considering different sampling methods, stratified sampling includes the steps: _______. Select the correct answer below: divide the population into groups; use simple random sampling to identify a proportionate number of individuals from each group list the members of the population; use simple random sampling to select a starting point in the population; let k = (number of individuals in the population)/(number of individuals needed in the sample); choose every kth individual in the list starting with the one that was randomly selected identify individuals of the population that are easily accessible; obtain data from these individuals use simple random sampling to select a set of groups; every individual in the chosen groups is included in the sample 7. When is using a simple random sample appropriate? Select the correct answer below: A simple random sample should always be used if possible. A simple random sample should be used if the population is not well understood or there are no groups within the population that need to be analyzed individually. A simple random sample should be used when the population has well-defined groups that are relatively homogeneous. This will make sure each group is represented proportionally. 8. Ruby is studying the mean waist size of all students attending her college. She collects data from the 25 students in her statistics class. Which type of sampling is used? Select the correct answer below: Systematic sampling Stratified sampling Convenience sampling Cluster sampling 9. A school district's superintendent wants to administer a test of life skills to a sample of students. The superintendent has