Fudykkydeo6ee6orl6rly fjfijt
1 answer:
You might be interested in
Answer:
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.
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 .
So it is z with a pvalue of , so
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 5.4 - 0.04 = 5.36 years.
The upper end of the interval is the sample mean added to M. So it is 5.4 + 0.04 = 5.44 years.
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.
For this case we must find 35% of 280.
Kerrie gets 10% and then 25%. So:
10% of 280:
280 ------------> 100%
x -----------------> 10%
Where "x" represents the amount given by 10% of 280.
Thus, 10% of 280 is 28.
Now, we find 25% of 280:
280 ------------> 100%
x -----------------> 25%
Where "x" represents the amount given by 25% of 280.
Thus, 25% of 280 is 70.
So we have that 35% of 280 is given by:
So, Kerrie's solution is correct.
Answer:
Option A