2.Beth is 6 years younger thantwice her brother's age. How old isBeth?
1 answer:
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Answer:
Step-by-step explanation:
utilise the Foil method to expand brackets:
F - mulply the first terms (x and x)
O - multiply the outside terms ( x and -2)
I - multiply the inside terms (5 and x)
L - multiply the last terms (5 and -2)
Then add them as following:
Then combine like terms:
Answer:
A normal distribution or z-test is used to construct a confidence interval.
Step-by-step explanation:
We are given the following in the question:
Sample mean, = $3120
Sample size, n = 40
Population standard deviation, σ = $677
The distribution of earnings of college is a normal distribution.
Conditions:
- Since we are given the population standard deviation and the the sample size is also greater than 30.
Conclusion:
Thus, we use a normal distribution or z-test to construct a confidence interval.