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

no, the equation would be invalid since they are both not equal.

step-by-step explanation:

here you got

4y-6+4y 2-9

first, you would simplify the equation on the form.

4y-6+4y 2-9

then, move all the terms that contains a y to the left and all the other terms to the right.

+4y-4y+-9-6

finally, you will simplify the left and the right side of the equation.

y=-3

529 and 531

step-by-step explanation: