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Statistics: test of means, test of proportions

1) A normal tomato will gain an average of 2 ounces per week during the growing season. A sample of 100 tomatoes is given a special hormone to increase their growth. The average weight gain of tomatoes in the sample was 3 ounces with a standard deviation of 1 ounce. Conduct a hypothesis test to determine if the hormone increased the tomatoes weight gain (Hint: ). Assume Alpha = .01 and remember to clearly state your null and alternate hypothesis as well as your conclusion about the average weight gain of the tomatoes.

2) The U.S. government recently reported that the proportion of people feeling negative about the economy was only 30%. However, a recent poll by CNN/Gallup found that in a sample of 1000 people 450 of them felt negative about the economy. Conduct a hypothesis test to determine if the proportion of people feeling negative about the economy is really 30% or not (Hint: ). Assume Alpha = .05 and remember to clearly state the null and alternate hypothesis as well as your conclusion about the proportion of people who are feeling negative about the economy.

3) In a sample of 1000 male doctors in the U.S. found that their average salary was $160,000 per year with a standard deviation of $25,000. Another sample of 1000 female doctors in the U.S. found that their average salary was $140,000 per year with a standard deviation $15,000. Conduct a hypothesis test to determine if the average salary of male doctors is the same as the average salary for female doctors (Hint: ). Assume Alpha = .05 and remember to clearly state the null and alternate hypothesis as well as your conclusion about the average salary of male doctors vs. female doctors.

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