Question

I failed my quiz and need help understand these problems for my online class

Answer 1

D. 2.81

Explanation:

To find the critical value that corresponds to a 99.5% confidence level, we follow the steps below.

Step 1: Subtract the confidence level from 100% to find the α level.

`100\%-99.5\%=0.5\%`

Step 2: Convert the result from Step 1 to a decimal.

`0.5\%=(0.5)/(100)=0.005`

Step 3: Divide Step 2 by 2 (this is called “α/2”) to find the area in each tail.

`(\alpha)/(2)=(0.005)/(2)=0.0025`

Step 4: Subtract the result in Step 3 from 1. This is because we want the area in the middle, not the area in the tail.

`1-0.0025=0.9975`

Step 5: Look up the area from Step in the z-table.

0.9975 comes up under 2.8+0.01 = 2.81

The value is 2.81