Find the critical value z Subscript alpha divided by 2 that corresponds to the confidence level 90%.

For this problem we know that the confidence level is 90% so then we can find the significance level with:

Then the value of and we can find a quantile who accumulate 0.05 of the area on each tail of the normal standard distribution and for this case the critical values are:

Step-by-step explanation:

For this problem we know that the confidence level is 90% so then we can find the significance level with:

Then the value of and we can find a quantile who accumulate 0.05 of the area on each tail of the normal standard distribution and for this case the critical values are:

50.6

step-by-step explanation: