The scores on a final exam were approximately normally distributed with a mean of 82 and a standard deviation of 11. if 85 students took the exam, and above a 60 is a passing grade, how many students failed the exam?

In this case, we can use the z statistic to find for the proportion of students who failed the exam. The formula for z score is given as:

t = (x – u) / s

where,

x = the sample score = 60

u = sample score mean = 82

s = standard deviation = 11

Substituting all given values into the equation:

t = (60 – 82) / 11

t = - 2

Based from the standard proportion distribution tables for z, this corresponds to:

P = 0.0228

This means that 2.28% of the students failed the exam or equivalent to:

failed students = (0.0228) * 85 = 1.938

approximately 2 students failed the exam

use the power rule  

( a b ) n = a n b n

to distribute the exponent.

apply the product rule to  

3 x 2 y 3 . ( 3 x 2 ) 2 ( y 3 ) 2

apply the product rule to  

3 x 2 . 3 2 ( x 2 ) 2 ( y 3 ) 2

raise  

3

to the power of  

2 . 9 ( x 2 ) 2 ( y 3 ) 2 multiply the exponents in   ( x 2 ) 2

.

apply the power rule and multiply exponents,  

( a m ) n = a m n . 9 x 2 ⋅ 2 ( y 3 ) 2

multiply  

2   by   2 . 9 x 4 ( y 3 ) 2

multiply the exponents in  

( y 3 ) 2 .

apply the power rule and multiply exponents,  

( a m ) n = a m n . 9 x 4 y 3

⋅

2

multiply  

3   by   2 . 9 x 4 y 6

step-by-step explanation:

squares, rhombus, rectangles