Example of two forces shown act on the structural member of AB. Determine the magnitude of P such that the resultant of these forces is directed along AB.
A door-to-door encyclopedia salesperson is required to document five in-home visits each day. Suppose that she has a 30% chance of being invited into any given home, with each address representing an independent trial. What is the probability that she requires eight houses to achieve her: (10) (i) Less than five success (ii) First success
Research Question:
To what extent do USF students understand and have awareness of fundamental implications pertaining to global health and well-being?
NEM1002 – Statistics for Decision Making PBL Activity – Descriptive Stats Your task is to select one of the four data sets supplied for analysis. In each data set there are 2000 pieces of data. You are required to take three (3) independent random samples from your chosen set. It is envisaged that each of the complete data sets are Normally Distributed (i.e. the Bell Shaped Curve). Please complete the following tasks and present your results and findings in a report. TASK 1. Obtain 3 independent random samples of all different (random) sizes. Samples should be no larger than 100 and no smaller than 40. Use the random number generator and random sampler function in Excel to complete this task (User instructions will be posted on VU Collaborate to assist you with this task). 2. Construct a Frequency Table and Histogram for each sample. 3. Find the Minimum, Q1, Median, Q3, and Maximum and then construct a Box Plot for each sample. There are many apps on the internet that can create an excellent electronic version of a Box Plot. 4. Calculate the means and standard deviations of each of the samples. 5. For each of the samples, confirm or otherwise, whether the 68-95-99.7% rule fits to the samples created. 6. Produce a report that will present your results, calculations and findings. The report should contain the following sections (but not limited to): a. Title Page b. Introduction c. Statistical Analysis and Calculations d. Findings (Did the samples infer that the data followed a Normal Distribution? Did the samples show any consistency? What other patterns (or abnormalities) were observed?). e. Conclusion
Identify distributions, Part I. Four plots are presented below. The plot at the top is a distribution for a population. The mean is 10 and the standard deviation is 3. Also shown below is a distribution of (1) a single random sample of 100 values from this population, (2) a distribution of 100 sample means from random samples with size 5, and (3) a distribution of 100 sample means from random samples with size 25. Determine which plot (A, B, or C) is which and explain your reasoning.
- 2. 3. Student: Brian Luth Date: 07/02/20 Instructor: Robson De Andrade Course: MAT220_33_Statistics I_2020_21_TERM1 Assignment: UNIT 1 - Section 1.4 - 1.6 Homework Which sampling method does not require a frame? Choose the correct answer below. A. Stratified B. Simple random C. Systematic D. Cluster E. All of the above sampling methods require a frame Determine whether the following statement is true or false. Explain. When obtaining a stratified sample, the number of individuals included within each stratum must be equal. Choose the correct answer below. A. False. A stratified sample is constructed by successively selecting a stratum at random and then selecting a random individual from within that stratum. With this process, it is unlikely that all strata will be sampled from the same number of times. B. False. When taking a stratified sample, a simple random sample is drawn from one stratum at random. All other strata will not be included in the sample. C. False. Within stratified samples, the number of individuals sampled from each stratum should be proportional to the size of the strata in the population. D. True. Sampling the same number of people from each stratum will result in a sample that is representative of the population at a lower cost than a simple random sample. To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at selects every th that comes off the assembly line starting with the until she obtains a sample of . General Electric 15 refrigerator seventh 30 refrigerators What type of sampling is used? A. Systematic B. Cluster C. Simple random D. Stratified E. Convenience
4. 5. 6. 7. To determine customer opinion of their , randomly selects during a certain week and surveys all . safety features Toyota 120 dealerships customers visiting the dealerships What type of sampling is used? A. Convenience B. Cluster C. Systematic D. Stratified E. Simple random wants to administer a satisfaction survey to its current customers. Using their customer database, the company randomly selects customers and asks them about their level of satisfaction with the company. IBM 50 What type of sampling is used? A. Convenience B. Simple random C. Stratified D. Cluster E. Systematic A club wants to sponsor a panel discussion on an upcoming election. The club wants to have four of its members lead the panel discussion. To be fair, however, the panel should consist of two members of each party. Below is a list of members in each party. Obtain a stratified sample of two people from party 1 and two from party 2. Party 1 Party 2 Bolden Nolan Cooper Ochs Carter Pawlak Engler Rice Haydra Tate Keating Thomas Lukens Wright May Weber Which of the following is a possible list of club members to lead the panel discussion? A. Pawlak, Nolan, Wright, Cooper B. Pawlak, Nolan, Wright, Carter C. Cooper, Keating, May, Pawlak D. Cooper, Keating, May, Rice E. Pawlak, Nolan, Cooper, Keating The human resource department at a certain company wants to conduct a survey regarding worker benefits. The department has an alphabetical list of all employees at the company and wants to conduct a systematic sample of size . 7707 70 (a) What is k? k = (b) Determine the individuals who will be administered the survey. Randomly select a number from 1 to k. Suppose that we randomly select . Starting with the first individual selected, the individuals in the survey will be
8. 9. For a poll of voters regarding a referendum calling for a national , design a sampling method to obtain the inviduals in the sample. Be sure to support your choice. renewable energy incentive Which sampling method would most likely be used in a poll of voters regarding a referendum calling for a national renewable energy incentive? A. Use stratified random sampling. Since this is a national issue, different geographical locations are likely to have similar views. B. Use simple random sampling. Simple random sampling is always the best sampling method to choose regardless of the survey conducted. C. Use convenience sampling. A large number of voters is needed to accurately reflect the nation’s voters; so a quick way to collect information is needed. D. Use cluster sampling. Each geographical region can be treated as a mini-population because voting results are independent of region. E. Use systematic random sampling. By varying the k-value, a sampling of the whole nation can be selected to achieve the needed accuracy. What is a closed question? What is an open question? Discuss the advantages and disadvantages of each type of question. What is a closed question? What is an open question? A. A closed question always has yes or no answers, whereas an open question is a free-response question. B. A closed question has many correct answers, whereas an open question has only one correct answer. C. A closed question has fixed choices for answers, whereas an open question is a free-response question. D. A closed question is a free-response question, whereas an open question has fixed choices for answers. Discuss the advantages and disadvantages of each type of question. A. Closed questions are harder to analyze, because they limit the responses. Open questions allow respondents to state exactly how they feel, but are easier to analyze due to the variety of answers. B. Closed questions allow respondents to state exactly how they feel, but are harder to analyze due to the variety of answers and possible misinterpretation of answers. Open questions are easier to analyze, but limit the responses. C. Closed questions are easier to analyze, but limit the responses. Open questions allow respondents to state exactly how they feel, but are harder to analyze due to the variety of answers and possible misinterpretation of answers. D. Closed questions are easier to analyze, because they usually gather more accurate data. Open questions limit the responses, but are harder to analyze since not every viewpoint will be covered.
10. 11. The following survey has bias. (a) Determine the type of bias. (b) Suggest a remedy. Suppose a survey regarding the sleeping habits of students is being conducted. From a list of registered students, a researcher obtains a simple random sample of 150 students. One survey question is “How much sleep do you get?” (a) What is the type of bias? Nonresponse bias Response bias Sampling bias (b) What is a possible remedy? Use systematic random sampling. Reword the question. Conduct face-to-face or telephone interviews. A poll is being conducted to obtain a sample of the population of an entire country. What is the frame for this type of sampling? Who would be excluded from the survey and how might this affect the results of the survey? using random digit dialing, which means a computer randomly generates phone numbers of landlines What is the frame for this type of sampling? A. The frame is people who like to talk on the phone. B. The frame is anyone with a landline phone. C. The frame is people who are home during the day. D. The frame is the entire population of the country. Who would be excluded from the survey and how might this affect the results of the survey? A. This could result in sampling bias due to undercoverage. Any household without a landline phone, households on the do not call registry, and homeless individuals are excluded. B. is excluded. This could result in sampling bias due to undercoverage. Any person that does not like to talk on the phone C. This could result in nonresponse bias due to people not participating in the poll. Any household without a landline phone, households on the do not call registry, and homeless individuals are excluded. D. There is nobody that is being excluded from the survey