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Hypothesis Testing & Normal Probability

The average monthly gasoline (gallon) purchase for a family with 2 cars is 62 gallons.This statistic has a normal distribution with a standard deviation = 6 gallons. A family is chosen at random.

a)Find the probability that the family's monthly gasoline (gallon) purchases will be between 47 and 67 gallons.

For the following ststement , write the null hypothesis and the alternate hypothesis. Then, label the one that is the claim being made.
An internest service provider claims that the mean download speed is more than 100k.
A manufacturer claims that the mean lifetime of it's florescent bulbs is 1050 hours. A homeowner selects 40 bulbs and finds the mean lifetime to be 1030 hours with a standard deviation of 80 hours. Test the manufacturers claim. Use alpha = 0.08.

Solution Summary

The solution provides step by step method for the calculation of test statistic for population mean and normal probability using z score. Formula for the calculation and Interpretations of the results are also included. Interactive excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.