Lunch is being served to members of a club. Each member orders a sandwich by choosing one type of bread, one kind of meat, and o
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<h2>Hello!</h2>
The answer is: George made his first mistake in Step 1.
<h2>Why?</h2>Getting a result of 26 cars needed means that he didn't take in consideration the next month in the mean calculation.
We have information of the number of sold cars of the first seven months, but if he wants to calculate the number of cards he needs to have a mean of 24 sold cards next months, he should take in consideration an extra month (the eighth month).
Checking the mistake:
So, it proves that he made a mistake by multiplying it into 7 and instead into 8
The correct answer would be:
He needed to include the eighth month in order to calculate how many cars he should sell next months in order to have a mean of 24 cars.
Have a nice day!
Answer:
C) 11
Step-by-step explanation:
1) Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
represent the sample mean for the sample
population mean (variable of interest)
s represent the sample standard deviation
n represent the sample size
Since the Confidence is 0.90 or 90%, the value of and
, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that
The margin of error is given by this formula:
And on this case we have that ME =7 and we are interested in order to find the value of n, if we solve n from the last equation we got:
And replacing the values that we got we have:
C) 11