Base times height equals area of a parallelogram
50 degrees because 50+50= 100 +80 = 180 and there is 180 degrees in a triangle
Answer:
At least 547 records need to be studied.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence interval
, we have the following confidence interval of proportions.

In which
Z is the zscore that has a pvalue of
.
And the margin of error is:

95% confidence interval
So
, z is the value of Z that has a pvalue of
, so
.
In this problem, we have that:






At least 547 records need to be studied.
The answer is 91 and the property used is the Identity Property of Addition.