Answer:
a) (1215, 1297)
b) (1174, 1338)
c) (1133, 1379)
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 1256
Standard Deviation, σ = 41
Empirical Rule:
- Also known as 68-95-99.7 rule.
- It states that almost all the data lies within three standard deviation for a normal data.
- About 68% of data lies within 1 standard deviation of mean.
- About 95% of data lies within two standard deviation of mean.
- About 99.7% of data lies within 3 standard deviation of mean.
a) range of years centered about the mean in which about 68% of the data lies

68% of data will be found between 1215 years and 1297 years.
b) range of years centered about the mean in which about 95% of the data lies

95% of data will be found between 1174 years and 1338 years.
c) range of years centered about the mean in which about all of the data lies

All of data will be found between 1133 years and 1379 years.
31. There are C(5, 2) = 10 ways to choose 2 colors from a group of 10 colors if you don't care about the order. (Here, we treat blue background with violet letters as being indistinguishable from violet background with blue letters.)
Only one of those 10 pairs is "B and V", so the probability is 1/10.
a) P(B and V) = 10%
32. The 12 inch dimension on the figure is 0 inches for the cross section. The remaining dimensions of the cross section are
c) 5 in. × 4 in.
_____
C(n, k) = n!/(k!·(n-k)!)
C(5, 2) = 5!/(2!·3!) = 5·4/(2·1) = 10
So slope intercept form y=mx+b slope is m
m=6 so
y=6x+b
this is not the legit way but it works so
put in 3 for x and 4 for y and solve for b
4=6(3)+b
4=18+b
-14=b
b=-14
the slope intercep form is y=6x-14
28x + 44y = 964.40
21x + 33y = 723.30
Let's multiply the first equation by 4 and the second by -4
84x + 176y = 3857.6
-84x - 132y = -2893.2
Add the equations together.
0 + 44y = 964.4
Simplify
44y = 964.4
Divide both sides by 44
y = 964.4/44
Since we have the value of y, let's plug 964.4/44 into y for the first equation.
28x + 44(964.4/44) = 964.40
Simplify the left side
28x + 964.4 = 964.4
Subtract 964.4 from both sides
28x = 0
Divide both sides by 0
x = 0
In conclusion,
y = 964.4/44
x = 0