Tracie rides the bus home from school each day. The graph represents her distance from home relative to the number of minutes si
2 answers:
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The 15% off sale is better because you save $14.69 more than with the $25 coupon.
Answer:
Step-by-step explanation:
According to the given information, we have
Sample size : n= 50
Since population standard deviation is unknown, so we use t-test.
Critical value for 95 percent confidence interval :
Confidence interval :
Required 95% confidence interval :
Answer:
The 95% confidence interval for the proportion of all shoppers during the year whose visit was because of a coupon they'd received in the mail is (0.2016, 0.2694)
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 for the proportion of all shoppers during the year whose visit was because of a coupon they'd received in the mail is (0.2016, 0.2694)