Answer:
The mean is 77.8125
Step-by-step explanation:
The mean is the average of the numbers. It is very easy to calculate and get. All you have to do is add up all the numbers and divide it by how many numbers there are.
80 + 90 + 81 + 86 + 100 + 77 + 75 + 96 + 65 + 87 + 58 + 80 + 36 + 73 + 70 + 91 = 1245
You need to work backwards
if it is no more than 9 units away from 8
thus x must be 8-9<x<8+9 solving -1<x<17
so the answer is 4.
20% of 124.95 is close to $125 so that is equal of 12.50 of 10% so multiply by 2 which is $25.00 so the estimate discount of the jacket will be $25.00
<span>Dawn was at 6 am.
Variables
a = distance from a to passing point
b = distance from b to passing point
c = speed of hiker 1
d = speed of hiker 2
x = number of hours prior to noon when dawn is
The first hiker travels for x hours to cover distance a, and the 2nd hiker then takes 9 hours to cover that same distance. This can be expressed as
a = cx = 9d
cx = 9d
x = 9d/c
The second hiker travels for x hours to cover distance b, and the 1st hiker then takes 4 hours to cover than same distance. Expressed as
b = dx = 4c
dx = 4c
x = 4c/d
We now have two expressions for x, set them equal to each other.
9d/c = 4c/d
Multiply both sides by d
9d^2/c = 4c
Divide both sides by c
9d^2/c^2 = 4
Interesting... Both sides are exact squares. Take the square root of both sides
3d/c = 2
d/c = 2/3
We now know the ratio of the speeds of the two hikers. Let's see what X is now.
x = 9d/c = 9*2/3 = 18/3 = 6
x = 4c/d = 4*3/2 = 12/2 = 6
Both expressions for x, claim x to be 6 hours. And 6 hours prior to noon is 6am.
We don't know the actual speeds of the two hikers, nor how far they actually walked. But we do know their relative speeds. And that's enough to figure out when dawn was.</span>
