Suppose that replacement times for washing machines are normally distributed with a mean of 9.3 and...

Suppose that replacement times for washing machines are normally distributed with a mean of 9.3 and a standard deviation of 1.1 years. Find the probability that 70 randomly selected washing machines will have a mean replacement time less than 9.1 years.

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orchestra answered 2 years ago

Replacement times for Timex watches are normally distributed with a mean of 10.2 years and a...

Replacement times for Timex watches are normally distributed with a mean of 10.2 years and a standard deviation of 3.1 years (Based on data from “Getting Things Fixed”, Consumer Reports). a. What percentage of watches should last between 8 and 9 years? b. At least how many years should the longest 25% of all watches last? c. If Timex wants to provide a warranty so that only 1% of the watches will be replaced before the warranty expires, what is...

Replacement times for TV sets are normally distributed with a mean of 8.2 years and a...

Replacement times for TV sets are normally distributed with a mean of 8.2 years and a standard deviation of 1.1 years. (Change the final answer to a % and keep 2 decimal places) a) Find the probability that a randomly selected TV set will have a replacement time between 9.5 and 10.5 years. (Include diagram) b) Find the probability that 35 randomly selected TV sets will have a mean replacement time less than 8.0 years. (Include diagram)

4. Replacement times for TV sets are normally distributed with a mean of 8.2 years and...

4. Replacement times for TV sets are normally distributed with a mean of 8.2 years and a standard deviation of 1.1 years. (Change the final answer to a % and keep 2 decimal places) a) Find the probability that a randomly selected TV set will have a replacement time between 9.5 and 10.5 years. (Include diagram) b) Find the probability that 35 randomly selected TV sets will have a mean replacement time less than 8.0 years. (Include diagram)

Suppose the average bus wait times are normally distributed with an unknown population mean and a...

Suppose the average bus wait times are normally distributed with an unknown population mean and a population standard deviation of of five minutes. A random sample of 30 bus wait times are taken and has a sample mean of 25 minutes. Find a 95% confidence interval estimate for the population mean wait time.

1) suppose average pizza delivery times are normally distributed with an unknown population mean and a...

1) suppose average pizza delivery times are normally distributed with an unknown population mean and a population standard deviation of 6 minutes. A random sample of 28 pizza delivery restaurants is taken and has a sample mean delivery time of 36 minutes. Find a 90% confidence interval estimate for the population mean delivery time.

Company XYZ know that replacement times for the DVD players it produces are normally distributed with...

Company XYZ know that replacement times for the DVD players it produces are normally distributed with a mean of 4.7 years and a standard deviation of 2.3 years. Find the probability that a randomly selected DVD player will have a replacement time less than -0.8 years? P(X < -0.8 years) = Enter your answer accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted. If the company wants to provide a...

Replacement time for TV sets are normally distributed with a mean of 7.2 years and a...

Replacement time for TV sets are normally distributed with a mean of 7.2 years and a standard deviation of 1.1 years. A) Find the probability that a randomly selected TV will have a replacement time less than 5.0 years. B) If you want to provide a warranty so that only 1% of the TV sets will be replaced before the warranty expires, what is the length of the warranty? I am unfamiliar with using a Stand Normal Distribution chart, if...

Company XYZ know that replacement times for the quartz time pieces it produces are normally distributed...

Company XYZ know that replacement times for the quartz time pieces it produces are normally distributed with a mean of 15.4 years and a standard deviation of 1.8 years. Find the probability that a randomly selected quartz time piece will have a replacement time less than 9.8 years? P(X < 9.8 years) = __________ Enter your answer accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted. If the company wants...

suppose average pizza delivery times are normally distributed with unknown population mean and population standard deviation...

suppose average pizza delivery times are normally distributed with unknown population mean and population standard deviation of 6. A random sample of 28 pizza delivery restaurants is taken and has a sample mean of delivery time of 36 minutes. Show your work. A. find critical value of 99% confidence level b. sketch graph c. what distribution should you use for this problem d. calculate error bound e. lower endpoint upper endpoint

The delivery times for a distributing site are normally distributed with an unknown population mean and...

The delivery times for a distributing site are normally distributed with an unknown population mean and standard deviation. If a random sample of 25 deliveries is taken to estimate the mean delivery time, what t-score should be used to find a 98% confidence interval estimate for the population mean? df t0.10 t0.05 t0.025 t0.01 t0.005 ... … … … … … 21 1.323 1.721 2.080 2.518 2.831 22 1.321 1.717 2.074 2.508 2.819 23 1.319 1.714 2.069 2.500 2.807 24...

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