# Question: A new type of smoke detector battery is developed From

A new type of smoke detector battery is developed. From laboratory tests under standard conditions, the half-life (defined as less than 50 percent of full charge) of 20 batteries are shown below.

(a) Make a histogram of the data and/or a probability plot. Do you think that battery half-life can be assumed normal?

(b) The engineers say that the mean battery half-life will be 8,760 hours with a standard deviation of 200 hours. Using these parameters (not the - sample), set up the centerline and control limits for the x chart for a subgroup size of n = 5 batteries to be sampled in future production runs.

(c) Repeat the previous exercise, but this time, use the sample mean and standard deviation.

(d) Do you think that the control limits from this sample would be reliable? Explain, and suggest alternatives.

(a) Make a histogram of the data and/or a probability plot. Do you think that battery half-life can be assumed normal?

(b) The engineers say that the mean battery half-life will be 8,760 hours with a standard deviation of 200 hours. Using these parameters (not the - sample), set up the centerline and control limits for the x chart for a subgroup size of n = 5 batteries to be sampled in future production runs.

(c) Repeat the previous exercise, but this time, use the sample mean and standard deviation.

(d) Do you think that the control limits from this sample would be reliable? Explain, and suggest alternatives.

## Answer to relevant Questions

A box of Wheat Chex cereal is to be filled to a mean weight of 466 grams. The lower specification limit is 453 grams (the labeled weight is 453 grams) and the upper specification limit is 477 grams (so as not to over fill ...A large retail toy store finds that, on average, a certain cheap (under $20) electronic toy has a 5 percent damage rate during shipping. From each incoming shipment, a sample of 100 is inspected. (a) Find the control limits ...Which type of statistic (descriptive, inferential) is each of the following? a. Estimating the default rate on all U.S. mortgages from a random sample of 500 loans. b. Reporting the percent of students in your statistics ...Which statement is false? Explain. a. If μ = 52 and σ = 15, then X = 81 would be an outlier. b. If the data are from a normal population, about 68 percent of the values will be within c. If μ = 640 and σ = 128 then the ...Which statement is correct? Why not the others? a. Likert scales are interval if scale distances are meaningful. b. Cross-sectional data are measured over time. c. A census is always preferable to a sample.Post your question