There is a probability of 77% that the mean of this sample is between 19.25 hours and 21.0 hours
Z score is used to determine by how many standard deviations the raw score is above or below the mean. The z score is given by:

Given that μ = 20, σ = 7, n = 125.
For x = 19.25:

From the normal distribution table, P(-1.20 < z < 0.62) = P(z < 0.62) - P(z < -1.2) = 0.8849 - 0.1151 = 0.7698 = 77%
There is a probability of 77% that the mean of this sample is between 19.25 hours and 21.0 hours
Find out more on z score at: brainly.com/question/25638875
Step-by-step explanation:
B(-2,3)
C(1,0)
F(-1,-2)
E(0,-4)
Answer:
The answer is 55.
Step-by-step explanation:
hope this helps
2³×(15-9)+7
=8(15-9)+7
=120-72+7
=48+7
=55
If the sides are in the ratio of 11:16:24, it means that they are all multiples of a same number x, according to these factors.
So, the shorter side is 11x feet long, the middle one is 16x feet long, and the longest side is 24x feet long.
This means that the perimeter is
feet long. But we know that this is 510 feet, so we have
.
So, the three sides are 110, 160 and 240 feet long.
To find the area of a triangle knowing its three sides, you can use Heron's formula, which states that, if
is half the perimeter of the triangle whose sides are
, the area
is given by

In our case,
so the formula becomes

You Just want to get Fahrenheit alone on one side of the equal sign. Your teacher forgot to use parenthesis. The correct equation for Celsius to Fahrenheit is:
Which will give you a completely different answer.... 
****
We will solve it using what is given:
C = (5/9)F - 32
C + 32 = (5/9)F
9(C + 32) = 5F
(9/5)(C + 32) = F
** If they mark you wrong, and try to say the answer is F = (9/5)C + 32 then they shouldn't be teaching math, and you should point out the fact there are no parenthesis around the F - 32 in the given formula.