An analysis of the grades on the first test in history 101 revealed that they approximate a normal curve with a mean of 75 and a standard deviation of 8. the instructor wants to award the grade of a to the upper 10% of the test grades. to the nearest percent, what is the dividing point between an a and a b grade?
select one:
a. 80
b. 85
c. 90
d. 95

b. 85

Step-by-step explanation:

Average grade (μ) = 75

Standard deviation (σ) = 8

Assuming a normal distribution, the z-score corresponding to the upper 10% of the test grades is z = 1.28.

The minimum grade 'X' within the top 10% is given by:

Rounding to the nearest percent, the dividing point between an A and a B grade is 85.

the answer is the option b

the range is all real numbers

step-by-step explanation:

we know that

the absolute value parent function is equal to

see the attached figure to better understand the problem

so

a. it is v-shaped > is true

b. the range is all real numbers > is not true

because the range is the > [0,∞)

all real numbers greater than or equal to zero

c. it goes through the origin > is true

d. the domain is all real numbers > is true

step-by-step explanation: