Assume You Are Interested In Doing A Statistical Survey
Assume That You Are Interested In Doing A Statistical Survey And Using
Assume that you are interested in doing a statistical survey and using confidence intervals for your conclusion. Describe a possible scenario and indicate what the population is, and what measure of the population you would try to estimate (proportion or mean) by using a sample. What is your estimate of the population size? What sample size will you use? Why?
How will you gather information for your sample? Describe your process. What confidence percentage will you use? Why? Assume that you have completed the survey and now state your results using a confidence interval statement. You can make up the numbers based on a reasonable result.
Paper For Above instruction
In this paper, I will outline a hypothetical scenario for conducting a statistical survey utilizing confidence intervals to arrive at data-driven conclusions. The focus will be on defining the population, selecting the measure to estimate, determining sample size, data collection processes, choosing an appropriate confidence level, and interpreting the results through a confidence interval statement.
Scenario Description: Suppose I am interested in estimating the average number of hours college students spend studying per week. The population of interest consists of all college students enrolled across a large university system. The goal is to estimate the mean number of study hours so that university administrators can better understand student engagement and inform policy decisions related to academic support.
Population and Measure: The population comprises all undergraduate and graduate students enrolled at the university. The measure of interest is the average (mean) number of hours spent studying weekly, as this provides a continuous variable suitable for mean estimation rather than proportion. Accurately estimating this mean can help identify the level of student workload and inform educational support services.
Population Size and Sample Size: The total student population is approximately 50,000 students. To estimate this mean with adequate precision, I would initially calculate the required sample size using standard sample size formulas for means, considering a desired margin of error (e.g., ±1 hour), a reasonable estimate of population standard deviation (say, 3 hours based on pilot data), and a confidence level of 95%. Using the formula:
n = (Z2 * σ2) / E2
where Z is the Z-score corresponding to the chosen confidence level (1.96 for 95%), σ is the estimated standard deviation, and E is the margin of error. Substituting values:
n = (1.962 * 32) / 12 ≈ rock on calculator
which approximates to about 109 students. To account for potential nonresponses, I would increase the sample size by 20%, resulting in a target sample size of approximately 130 students.
Sampling Method and Data Collection: To ensure representatives from various departments, classes, and schedules, I would employ stratified random sampling. The student population would be divided into strata based on factors like academic level and major, and random samples would be drawn proportionally from each stratum. Data collection would be carried out through an online survey distributed via university email lists, ensuring confidentiality and encouraging honest responses. Participants would be asked to report their average study hours per week.
Confidence Level Choice: A 95% confidence level would be chosen, which is standard in social sciences, balancing confidence in the results with practical sample sizes. This level implies that if the survey were repeated multiple times, approximately 95% of the constructed confidence intervals would contain the true population mean.
Results and Confidence Interval Statement: Suppose the survey results indicate a sample mean of 15 hours with a sample standard deviation of 4 hours, based on 130 respondents. The confidence interval can be calculated as:
CI = sample mean ± Z * (sample standard deviation / √n)
Using Z = 1.96:
CI = 15 ± 1.96 (4 / √130) ≈ 15 ± 1.96 0.35 ≈ 15 ± 0.69
Thus, the 95% confidence interval is approximately (14.31, 15.69) hours. This means we are 95% confident that the true average number of study hours per week for all students at the university lies between about 14.31 and 15.69 hours.
In conclusion, applying statistical sampling and confidence intervals provides a reliable estimate of student study habits, guiding university policies aimed at academic improvement and student support programs.
References
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