30 students
14 have no siblings
that leaves 16 with siblings
6 have brothers and 12 have sisters which = 18 so 2 of the students have both a brother and a sister
2/30 students have a brother and a sister
1/15 chance
The correct answer is C-6 and two thirds
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.
Answer:
Total distance traveled = 1/3 + 1/2 = 2+3/6 = 5/6 miles
Hope this helps!
Step-by-step explanation: