Population Means and Proportions

Population Means and Proportions
Dawn Gallegos
BHS 220
Module 5
Dr. Ogbochi McKinney
8 June 2015
Test statistic and null hypothesis
Null hypothesis: H0: Physical exercises do no result to weight loss and physical fitness
Alternative hypothesis: H1: Physical exercises are associated with weight loss and improved physical fitness.
The hypothesis tests will focus on the 15 observations being nine and six observations for light to moderate intensity physical activities and vigorous intensity physical activities respectively. If the data is normally distributed, then it is expected that it is possible to determine whether to reject or not reject the null hypothesis. The student t- statistic can be used as the number of observations is less than 30. There is a need to focus on the standard deviation and differences in the means when using the student t-test test (Norman & Streiner, 2008). Even though, it is not possible to determine whether the calories lost result in weight loss, the analysis will show whether the samples are from the same population. There is an assumption that vigorous intensity physical activities result in higher weight loss since more calories are burned. At the same time, physical exercises also cause more calories to burn compared to the non-intervention programs where there is no exercise. The t-statistic further compares the mean and standard deviation of the two samples. While focusing on the correlation between variables, the sample size and normal distribution are taken into consideration (Peat &Barton, 2008).
Test statistic
The main difference between the two recorded data is that the intensity of physical activities and the length of time spent exercising also differed. There is a need to assess whether the statistical differences are significant. This is because there are huge divergences in each table and between the two tables. As such, the student t- statistic is appropriate to test the differences in the means, and the t-statistic is useful when the number of observations is small. The one sample t-test compares the means when participants are measured once, but the paired t-test compares means as well as paired-samples t-test (Norman & Streiner, 2008). The number of observations and likely standard errors also influence the choice of the t- statistic, as is the variance for each group. The sample size requirements influence the design of a study and interpreting the results, and when the sample size is large enough, there is better precisi...