A study of 100 apple trees showed that the average number of apples per tree was 2000. The standard deviation of the population is 200. Which of the following is the 90% confidence interval for the mean number of apples for all trees?
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The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the average,…
The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes. Using the .10 level of significance, can we conclude that the assembly time using the new method is faster?
Q18 A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces.
Q18 A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, the absorption amounts of a sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6, 3.8, 4.0, and 3.9. At a level of significance of 1%, would you claim that the new design is better than the old one? Selected Answer: No because we reject the Null hypothesis at Type 1 error = 1%. Answers:No because we don’t reject the Null Hypothesis at Alpha = .01. Yes because we reject the Null hypothesis […]
After an outbreak of diarrhea following a reception at an orchestra concert, you are charged with investigating the cause.
After an outbreak of diarrhea following a reception at an orchestra concert, you are charged with investigating the cause. What statistical test should be used to test the null hypothesis that the proportion of people becoming ill among those who ate at the reception to the proportion becoming ill among those who did not eat at the reception?
The expected (mean) life of a particular type of light bulb is 1000 hours with a standard deviation of 50 hours. The life of this bulb is normally…
1. The expected (mean) life of a particular type of light bulb is 1000 hours with a standard deviation of 50 hours. The life of this bulb is normally distributed. What is the probability that a randomly selected bulb would last longer than 1150 hours? 2. The average hourly wage of workers at a fast food restaurant is $6.50/hr with a standard deviation of $0.45. Assume that the distribution is normally distributed. If a worker at this fast food restaurant is selected at random, what is the probability that the worker earns more than $6.75? 3. Let X be a normal […]
