Answer:
C
Step-by-step explanation:
I think you have to call a = 14/32 and b = 7/4
3a = 3 * 14/32 = 42/32
b = 1 3/4 = (4 + 3)/4 = 7/4
42/32 // 7/4 Invert and multiply
42/32 * 4/7 Cancel 4 into 32 and 7 into 42
6/8 = 3/4
I make the answer C
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)
A bus holds 40 people and a van holds 10
Answer:
p=7
Step-by-step explanation:
4p+5=33
33-5=28
4p=28
28/4=7
p=7
4(7)+5=33
28+5=33
In the 7th and 8th grade combined, there 3+5 girls = 8 girls, and 7+5 boys = 12 boys. If there are only boys and girls, then there are 12+8=20 students in all.
The fraction of girls out of the total is P = 8/20 = 2/5.