Between which pair of numbers is the exact product of 379 and8?
2 answers:
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Answer:
The 95% confidece estimate for how much a typical parent would spend on their child's birthday gift is between $37.47 and $46.53.
Step-by-step explanation:
The results were roughly normal, so we can find the normal confidence interval.
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 .
So it is z with a pvalue of , so
Now, find 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 42 - 4.53 = $37.47.
The upper end of the interval is the sample mean added to M. So it is 42 + 4.53 = $46.53.
The 95% confidece estimate for how much a typical parent would spend on their child's birthday gift is between $37.47 and $46.53.