15 = 5 x 3 = 5 x √3 x √<span>3
so
15 / (5</span><span> √</span>3)
= (5 x √3 x √3)/ (5 x √3) ............( 5 x √3 are canceled out)
= √3
or
= 1.73
We cannot calculate the confidence interval without the sample size. However, for the second question, the sample size needed would be 49.
The formula we use is
To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value is closest to a z-score of 2.33.
Using the z-score, our standard deviation (9) and our margin of error (3), we have:
Answer: There are 1800 unique names from both the lists.
Explanation:
Since we have given that
there are two lists :
In First list, number of names = 1200
In Second list, number of names = 900
According to question , we have also given that
there are 150 names that appear on both lists,
So,
Number of unique names in the first list is given by
Number of unique names in the second list is given by
Therefore, total number of unique names is given by
Hence, there are 1800 unique names from both the lists.