Answer:
The 95% confidence interval for the percent of all coffee drinkers who would say they are addicted to coffee is between 21% and 31%.
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
.
The margin of error is:

A confidence interval has two bounds, the lower and the upper
Lower bound:

Upper bound:

In this problem, we have that:

Lower bound:

Upper bound:

The 95% confidence interval for the percent of all coffee drinkers who would say they are addicted to coffee is between 21% and 31%.
Answer:
-11
Step-by-step explanation:
Answer:
Robyn model makes more sense and Marks is nonsense.
Step-by-step explanation:
In this question ,calculations not required .All we have to do is consider each model logically .
Marks
Marks model shows 20 rather than 2 which means 200 is 10 times as much as 20. It does not make any sense.
Robyn
Robyn model shows 2 which means 200 is 100 times as much as 2 and this is not only correct but also makes sense because 100 *2=200
Answer:
The price that is two standard deviations above the mean price is 4.90.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 3.22 and a standard deviation of 0.84.
This means that 
Find the price that is two standard deviations above the mean price.
This is X when Z = 2. So




The price that is two standard deviations above the mean price is 4.90.