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.
Starting off, we can multiply the third equation by 2 and add it to the third to get rid of both the x and y variables. Next, we get z=1. Plugging that into 3y-5z=-23, we get 3y-5=-23. Adding 5 to both sides, we get 3y=-18. After that, we can divide both sides by 3 to get y=-6. Plugging that into -2x-y-z=-3, we get -2x+6-1=-3=-2x+5. Subtracting 5x from both sides, we get -2x=-8. After that, we can divide both sides by -2 to get x=4.
Answer:
Step-by-step explanation: