Successive weekly sales, in units of one thousand dollars, have a bivariate normal distribution with common mean 40, common standard deviation 6, and correlation .6. (a) find the probability that the total of the next 2 weeks’ sales exceeds 90. (b) if the correlation were .2 rather than .6, do you think that this would increase or decrease the answer to (a)? explain your reasoning. (c) repeat (a) when the correlation is .2.

the solution has been given in the attachments

Step-by-step explanation:

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.

6 and 24

step-by-step explanation:

6 x 4 = 24