Answer:
x=0 ,y=3
if you have any questions about the way I solved it,don't hesitate to ask
If it is an apple, then it grows on trees.
Answer:
The confidence limits for the proportion that plan to vote for the Democratic incumbent are 0.725 and 0.775.
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
.
Of the 500 surveyed, 350 said they were going to vote for the Democratic incumbent.
This means that 
80% 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 confidence limits for the proportion that plan to vote for the Democratic incumbent are 0.725 and 0.775.
The mean is the average of the data set. Median is the value that separates the higher half and the lower half of the set of values. Mode is the value that occurs often in the data set. Therefore, the correct answer is option A, <span>mean = 9.7, median = 10, mode = 15</span>