Randall is 15 years younger than Wendy. 8 years ago, Wendy's age was 2 times Randall's age. How old is Randall now?
1 answer:
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Answer:
According to the Empirical Rule, 68% of the data should fall between 11.98 and 18.02
Step-by-step explanation:
We are given the following data in the question:
10, 11, 12, 13, 13, 13, 14, 15, 16, 16, 17, 18, 18, 19, 20
Formula:
where are data points,
is the mean and n is the number of observations.
Sum of squares of differences = 25 + 16 + 9 + 4 + 4+ 4 + 1 + 0+ 1+ 1 + 4 + 9 + 9+ 16 + 25 = 128
Empirical rule:
- According to this rule almost all the data lies within three standard deviation of the mean for a normal distribution.
- About 68% of data lies within one standard deviation of the mean.
- About 95% of data lies within two standard deviations of mean.
- Arround 99.7% of data lies within three standard deviation of mean.
Thus, by empirical rule,
According to the Empirical Rule, 68% of the data should fall between 11.98 and 18.02
Answer:
a = - 27
Step-by-step explanation:
- a - 6 = 12 ( add 6 to both sides )
- a = 18 ( multiply both sides by 3 to clear the fraction )
- 2a = 54 ( divide both sides by - 2 )
a = - 27