Answer:
a)
The 95% confidence interval would be given by (0.799;0.847)
b)
And rounded up we have that n=622
c)
And rounded up we have that n=1068
Step-by-step explanation:
Part a

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by
and
. And the critical value would be given by:
The confidence interval for the mean is given by the following formula:
If we replace the values obtained we got:
The 95% confidence interval would be given by (0.799;0.847)
Part b
The margin of error for the proportion interval is given by this formula:
(a)
And on this case we have that
and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
And replacing into equation (b) the values from part a we got:
And rounded up we have that n=622
Part c
And rounded up we have that n=1068
Answer:
5/36
Explanation:
Distance on a number line is basically difference between two numbers. So we subtract the two numbers. This can be solved on a calculator btw. 7/12 - √16/81 = 5/36.
Answer:
40.5 is what they are divided
Step-by-step explanation:
Assuming you mean simplified, 66/100=33/50, which can be achieved by dividing both the numerator and denominator by 2.
Answer: -0.36
Step-by-step explanation:
Given: Mean : 
Standard deviation : 
We know that the formula to calculate the z-score is given by :-

For x=8.2 minutes, we have

Hence, the z-score for this amount of advertising time = -0.36