Answer:
Write the written problem into an equation to get:
3x +2 = 5x -4
To solve:
Add 4 to each side:
3x+6 = 5x
Subtract 3x from each side:
2x = 6
Divide both sides by 2:
x = 6/2
x = 3
Step-by-step explanation:
Answer:
The median is 20.5
the average is 21
Step-by-step explanation:
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: The required ratio would be 3 miles : 4 minutes.
Step-by-step explanation:
Since we have given that
Speed of a cheetah = 45 miles per hour
So, it means
Distance = 45 miles
Time = 1 hour = 60 minutes
So, the ratio of the distance it travels to the time it takes would be
Distance : Time

Hence, the required ratio would be 3 miles : 4 minutes.