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)
1 1/2? I pretty sure this is the answer.
Answer:
4.5
Step-by-step explanation:
The equation of an area of a circle is A=πr² where r is the radius.
The radius is also half the diameter. So the radius of the quarter is 1.2
A=π(1.2)²
A=π(1.44)
A=4.52389
Answer:
Mariana has better performance.
Step-by-step explanation:
We are given that in a training session, Mariana made 12 of the 15 shots on goal that she kicked and Carla had an effectiveness of 75%.
And we have to find which girl's performance is better.
Since it is stated that Carla had an effectiveness of 75%.
Similarly, we will find the effectiveness of Mariana;
Total shots available to Mariana = 15 shots
Number of shots on goal = 12
So, her effectiveness = 
=
= 80%
This shows that Mariana has a better performance as compared to Carla as 80% > 75%.