The data represent the number of phone calls received over a 70day period.
day 1 2 3 4 5 6 7
calls received 5 2 9 8 3 1 0
what is the mean number of phone calls received?

Are you talking about 7-day period instead? Or is that really 70? 

Anyway, the mean number of phone calls received over the period of time given would be 4 calls. I got to this answer through adding all of the calls and dividing them by the number of days. 

P(1 black sock)= 6/14
P(2 black socks)= (6/14)^2
                          =36/196
                          =0.184