3n+(-7)= -1need to know what n equals to
2 answers:
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Answer:
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
That is z with a pvalue of , so Z = 1.28.
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 7.6 - 0.1 = 7.5
The upper end of the interval is the sample mean added to M. So it is 7.6 + 0.1 = 7.7
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Answer:
m = 6
Step-by-step explanation:
4m + 2(8) = 5(8) (Given)
4m + 16 = 40 (Simplify)
4m + 16 - 16 = 40 - 16 (Subtraction Property of Equality)
4m = 24 (Simplify)
(Division Property of Equality)
m = 6 (Simplify)