Answer:
For this case we know that the confidence level is 90% so then the significance level is 
and 
. And we can find in the normal standard distribution a value who accumulates 0.5 of the area on each tail and we got:
And the best option would be:
1.645
Step-by-step explanation:
We assume that the parameter of interest is 
and we can assume that the distribution for this parameter is normally distributed so then the confidence interval assuming a two sided interval is given by:
Where 
represent the estimator for the parameter, SE the standard error and 
the critical value.
For this case we know that the confidence level is 90% so then the significance level is and . And we can find in the normal standard distribution a value who accumulates 0.5 of the area on each tail and we got:
And the best option would be:
1.645
I think this is the steps your looking for.
Answer:
The measure of angle 6 is 62 degrees.
The measure of angle 3 is 64 degrees.
The measure of angle 8 is 54 degrees.
The measure of angle 4 is 64 degrees.
The measure of angle 12 is 32 degrees.
Step-by-step explanation:
