20 is 1/5 of 100 so do 20x5=100 and 15x5=75
So there is a 75% chance she will make the goal
Answer:
The mean is 11.5 minutes and the standard deviation is of 6.64 minutes
Step-by-step explanation:
An uniform probability is a case of probability in which each outcome is equally as likely.
For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.
The mean is:

The standard deviation is:

Arrival time of 9:18 am and a late arrival time of 9:41 am.
9:41 is 23 minutes from 9:18. So the time is uniformily distributed between 0 and 23 minutes, so a = 0, b = 23.
Mean:

Standard deviation:

The mean is 11.5 minutes and the standard deviation is of 6.64 minutes
Use cosine rule,
cos(A)=(b^2+c^2-a^2)/(2bc)
=(10^2+12^2-6^2)/(2*10*12)
=13/15
A=29.926 degrees.................................(A)
cos(B)=(c^2+a^2-b^2)/(2ca)
=(12^2+6^2-10^2)/(2*12*6)
=5/9
B=56.251 degrees.................................(B)
cos(C)=(a^2+b^2-c^2)/(2ab)
=(6^2+10^2-12^2)/(2*6*10)
=-1/15
C=93.823 degrees.................................(C)
Check:29.926+56.251+93.823=180.0 degrees....ok
I always prefer factoring, if there are simple factors.
There are simple factors here.
x² + 11x + 18 = 0
(x + 2) (x + 9) = 0
The left side is zero if either factor is zero.
First factor:
x + 2 = 0
<u>x = -2</u>
Second factor:
x + 9 = 0
<u>x = -9 </u>