Conclusions Memo: Baseball ERAThe purpose of the initial research was to examine the impact that ERA or earned run average has on a team's ability to win games. The research question to be answered was: If a team has an earned run average above the average for Major League Baseball will they win as many games as teams that have lower than average earned run averages. Answering this question will show how important the impact of ERA is on a team's ability to win games.
The initial conclusion was based on data analysis of the descriptive statistics for the wins of the sample group HiERA and LoERA. The data analysis was used to calculate the measures of central tendency, dispersion, skew, and frequency distribution. The determined mean HiERA was 74, while the mean LoERA was 87.125, and standard deviation HiERA was 10.49542025, while the standard deviation LoERA was 6.761410109. Given that simple standard deviations revealed such low numbers, the indication was that all the data for HiERA and LoERA was very close to the mean with little dispersion.
The alternate hypothesis was chosen because of the seemingly large difference in average wins between the HiERA and LoERA samples. Consequently, Team A determined to reject the null.
Using a confidence level of 95%, Team A came up with the computations for the confidence intervals. The confidence level is the percentage of times that the mean will fall within the calculated range for the confidence interval. Calculations show with both the LoERA mean of 87.25 and the HiERA mean of 74 that both of the numbers are well within the interval and can be considered accurate. Looking at these numbers also indicates if there is a significant difference in the groups. The LoERA mean and HiERA means do not fall into each...