The pH scale measures the amount of alkalinity or acidity in a liquid and ranges from 0-14. The ideal pH for a swimming pool is 7.2. A pH that is too high or low can cause discomfort for the swimmers, especially in the eyes. High variability in the pH readings across the swimming pool can be problematic. The following data shows seven pH readings that were taken at the Wilson Community Pool from different locations at 10 a. m. this morning. The average pH reading from this sample was 7.02 with a sample standard deviation of 0.40. Using α= 0.05 and the critical value approach, determine if correctiveaction is needed at this pool to adjust the pH value. Required:
State your conclusion.

a. Because calculated t statistic is greater than t critical value, we reject the null hypothesis. Therefore, Wilson Community Pool cannot conclude that the pH value is not equal to 7.2. Based on this sample, corrective action needs to be
taken.
b. Because calculated t statistic is less than critical t value, we reject the null hypothesis. Therefore, Wilson Community Pool cannot conclude that the pH value is not equal to 7.2. Based on this sample, corrective action needs to be
taken.
c. Because the t calculated is greater than the critical t, we fail to reject the null hypothesis. Therefore, Wilson Community Pool conclude that the pH value is equal to 7.2. Based on this sample, no corrective action is needed.
d. Because the t calculated is less than the critical t, we fail to reject the null hypothesis. Therefore, Wilson Community Pool conclude that the pH value is equal to 7.2. Based on this sample, no corrective action is needed.