Ateacher gives a test to a large group of students. the results are closely approximated by a normal curve. the mean is 74, with a standard deviation of 8. the teacher wishes to give a's to the top 8% of the students and f's to the bottom 8%. a grade of b is given to the next 16%, with d's given similarly. all other students get c's. find the bottom cutoff for a grade of c.

b. 6

step-by-step explanation:

we are given the table representing an exponential function.

we can see from the table that, as x is increasing, the value of y is increasing in the power of 6.

i.e. the following relation is obtained,

x = 1, y = 6

x = 2, y = 36 =

x = 3, y = 216 =

x = 4, y = 1296 =

x = 5, y = 7776 =

so, the geometric series obtained is .

thus, the common ratio is given by = = 6.

hence, the common ratio is 6.

the value of x is 28.2

we need to divide the number of toy dinosaurs, 156, by the number of brothers, 4:

in order to estimate, we can use compatible numbers:

156 ÷ 4

  ↓

160   ÷ 4 = 40        

the correct answer is a).