Answer:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
For this problem, we have that:
95% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
The lower limit of this interval is:
The upper limit of this interval is:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
Answer:
B
Step-by-step explanation:
Time taken by a regular bus to reach its destination = 3 1/4 hours
= 13/4 hours
Time taken by the express bus to make the same trip = 2 1/2 hours
= 5/2 hours
Time that can be saved by taking the express bus = (13/4) - (5/2) hours
= (13 - 10)/4 hours
= 3/4 hours
So 3/4 hours can be saved by taking the express bus rather than the regular bus. The correct option among all the options given in the question is option "C". I hope the procedure is simple enough for you to understand.
-11 y 17 with z and x on the line
(-2.7)0 = 0 [multiplication of 0 is 0]
