Answer:
59 to 66
Step-by-step explanation:
Mean test scores = u = 74.2
Standard Deviation =
= 9.6
According to the given data, following is the range of grades:
Grade A: 85% to 100%
Grade B: 55% to 85%
Grade C: 19% to 55%
Grade D: 6% to 19%
Grade F: 0% to 6%
So, the grade D will be given to the students from 6% to 19% scores. We can convert these percentages to numerical limits using the z scores. First we need to to identify the corresponding z scores of these limits.
6% to 19% in decimal form would be 0.06 to 0.19. Corresponding z score for 0.06 is -1.56 and that for 0.19 is -0.88 (From the z table)
The formula for z score is:

For z = -1.56, we get:

For z = -0.88, we get:

Therefore, a numerical limits for a D grade would be from 59 to 66 (rounded to nearest whole numbers)
Answer: I think the answer is B
Step-By-Step Explination:
First you find out what x is by doing 42 multiplying it by 0.1 witch equals 4.2 gallons per mile
Next you figure out what y is by doing 4.2y (witch is 4.2 times y)
It must be 6 since the length sides r doubled and it's similar
5x^2-4x+1 + -3x^2+x-3= 2x^2-3x-2
Answer:
We can think of it as the zeros after the decimal point.
Step-by-step explanation:
Negative exponents always move the number to the right putting the decimal in front of it.