The lifetime for a certain brand of widgets is normally distributed. A random sample of 25 widgets is taken and a sample mean lifetime of 520 hours with a standard deviation of 50 hours. Before taking the sample, researchers claimed that the mean lifetime of a widget was more than 500 hours. 1. null hypothesis: 2. the alternative hypothesis:
3. explain what test will be used and why?

1. H0: u = 500

2. H1: u <500

3. One sample t test

Step-by-step explanation:

1. The null hypothesis in this question would be

H0: u = 500

2. The alternative hypothesis would be

H1: u < 500

3. The test that we are going to be using is the one sample t test. This test is used to test hypothesis. It would make a comparison of h0 to the mean of the sample. Now we are using this here because the sample standard deviation was given

step-by-step explanation:

first you will have to convert 3/4 into a decimal

which is .75

then you will have to divide 1.5 by .75

which is 2

no you have to divide

no he doesnt because "-16' is negatiive

step-by-step explanation: