Explanation
Part A
We can use the formula below to find the mean.

We will then have;

Mean = 6.2632
Part B
Since the data set is odd.

Answer: From the column of cumulative frequency cf, the median is 7
The answer to your question is -50.
Answer:
Below.
Step-by-step explanation:
is also 
It will differ for any x besides 1 and 0 because you're multiplying x by itself, which makes the answer greater.
But, it's the same for 1 and 0 because they equal each other when you square them.
C=2πr=2·π·1≈6.28319
so the answer is 6.28