Answer:
2.275%
Step-by-step explanation:
The first thing to do here is to calculate the z-score
Mathematically;
z-score = (x-mean)/SD
from the question, x = 12,300 hours , mean = 11,500 hours while Standard deviation(SD) = 400 hours
Plugging the values we have;
z-score = (12,300-11,500)/400 = 800/400 = 2
Now, we want to calculate P(z ≤ 2)
This is so because we are calculating within a particular value
To calculate this, we use the z-score table.
Mathematically;
P(z ≤ 2) = 1 - P(z > 2) = 1 - 0.97725 = 0.02275
To percentage = 2.275%
The answer is
27/5 = 5 2/5 = 5.4
Answer:
(x-2)(y+1)
Step-by-step explanation:
1) a. x = number of cars
b. x - 12
2) a. x = number of packages
b. 16 + 1/2x
3) a. x = number of coins
b. 1/2x - 6
4) 17 + x = 78
Subtract 17 from each side.
x = 61
5) x - 33 = 78
Add 33 to each side.
x = 111
6) x * 84 = 327.6
Divide each side by 84
x = 3.9
7) 1333/8.6 = 155
The speed was 155mph.
8) 2475/110 = 22.5
The trip took 22 and a half hours. (Or "The trip took 22.5 hours."