60. 61. 62. 63. 64. 65. need to be added to the water to adjust the pH to the desired level. Fifteen pH readings were taken at the Wilson Community Pool from different locations at 10 AM this morning. The average pH reading from this sample was 7.02 with a standard deviation of 0.40. Using a = 0.05 and the critical value approach, determine if corrective action is needed at this pool to adjust the pH value. The pH scale measures the amount of alkalinity or acidity in a liquid and ranges from 0 to 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. Chemicals need to be added to the water to adjust the pH to the desired level. Fifteen pH readings were taken at the Wilson Community Pool from different locations at 10 AM this morning. The average pH reading from this sample was 7.02 with a standard deviation of 0.40. Using a = 0.05 and the pvalue approach, determine if corrective action is needed at this pool to adjust the pH value. Hallmark would like to test the hypothesis that those celebrating Valentine's Day will spend more than an average of $125 on gifts. A random sample of 18 people celebrating Valentine's Day spent an average of $148.50 with a standard deviation of $34.90. Hallmark would like to set a = 0.01. Use the critical value approach to test this hypothesis. ) Hallmark would like to test the hypothesis that those celebrating Valentine's Day will spend more than an average of $125 on gifts. A random sample of 18 people celebrating Valentine's Day spent an average of $148.50 with a standard deviation of $34.90. Hallmark would like to set a = 0.01. Use the p-value approach to test this hypothesis. John is considering investing in a Subway Sandwich franchise and would like to test the hypothesis that the average weekly sales exceeds $7,000. A random sample of 26 Subway stores had average weekly sales of $7,640 with a sample standard deviation of $2,410. Use the critical value approach to test this hypothesis using a = 0.05. John is considering investing in a Subway Sandwich franchise and would like to test the hypothesis that the average weekly sales exceeds $7,000. A random sample of 26 Subway stores had average weekly sales of $7,640 with a sample standard deviation of $2,410. Use the p-value approach to test this hypothesis using a = 0.05. Over the past several years, the proportion of one-person households has been increasing. The Census Bureau would like to test the hypothesis that the