The average weight of a package of rolled oats is supposed to be at least 18 ounces. A sample of 18 packages shows a mean of 17.78 ounces with a standard deviation of 0.41. At alpha/a = .05, what is the null hypothesis?

The mean consumption of water per household in a city was 1244 cubic feet per month. Due to a water shortage because of a drought, the city council campaigned for water use conservation by households. A few months after the campaign was started, the mean consumption of water for a sample of 96 households was found to be 1164 cubic feet per month. The population standard deviation is given to be 257 cubic feet. a. Find the p-value for the hypothesis test that the mean consumption of water per household has decreased due to the campaign by the city council. Would you reject the null hypothesis at a = 0.025? Round your answer to four decimal places. p-value = We i b. Make the test of part a using the critical-value approach and a = 0.025. Zobserved Round your answer for z to two decimal places. We Ho. i Ho. We conclude that the mean consumption of water per household has due to the campaign by the city council.

Standard x-ray machines should give radiation dosages below 5 mill roentgen. To test a certain x-ray machine a sample of 36 observations is taken with a mean of 4.13 m.and a standard deviation of 1.91m. calculate the p-value for this test statistic.

A factory that manufactures screws is performing a quality control experiment. Each object should have a length of no more than 13 centimeters. The factory believes that the length of the screws exceeds this value and measures the length of 70 screws. The sample mean screw length was 13.01 centimeters. The population standard deviation is known to be σ=0.15 centimeters. What is the null hypothesis? What is the alternative hypothesis?