Answer:
a)
And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %
b)
So one deviation below the mean we have: (100-68)/2 = 16%
c)
For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%
Step-by-step explanation:
For this case we have a random variable with the following parameters:
From the empirical rule we know that within one deviation from the mean we have 68% of the values, within two deviations we have 95% and within 3 deviations we have 99.7% of the data.
We want to find the following probability:
We can find the number of deviation from the mean with the z score formula:
And replacing we got
And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %
For the second case:
So one deviation below the mean we have: (100-68)/2 = 16%
For the third case:
And replacing we got:
For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%
B is the midpoint which means both sides are equal to each other:
5x = 3x + 4
Subtract 3x from both sides
2x = 4
Divide both sides by 2
X = 2
Well, just by looking at the beginning of the problem, Jamelia had made the common mistake of thinking that
(<span>8.4852...)
</span>is equal to
(12)
If you want to estimate a square root like 72, simply find squares that would fit around the number you are looking to find, in our case, 72.
So 9*9 is 81, which is too high and 8*8 is 64, which is too low. So you know that somewhere between those numbers is what your root of 72 is!
30% because 10 out of 10 is 100%.
So 3 out of 10 is 30%.
10m ----> 3 sec
x meters ----> 50 sec
50(10) = 3x
500 = 3x
devide both in 3
x = 166.66 m