Answer:
21.16
Step-by-step explanation:
Starting from the theory we have the following equation:
[tex]fi*P(x<c-1) = 0.99[/tex]
Using the data supplied in the exercise, we have subtracting the mean and dividing by the standard deviation:
[tex]P( z \leq \frac{c-1-12}{3.5}) =0.99/fi[/tex]
solving for "c", knowing that fi is a tabulating value:
[tex]\frac{c-13}{3.5}=0.99/fi\\\frac{c-13}{3.5}=2.33\\c-13=2.33*3.5\\c = 8.155 +13\\c = 21.155[/tex]
therefore the value of c is equal to 21.16
