Part 1). The following table lists the probability distribution of a discrete random variable x:
|
x
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
|
P(x)
|
0.15
|
0.34
|
0.23
|
0.13
|
0.07
|
0.06
|
0.02
|
The mean of the random variable x is:.
The standard deviation of the random variable x, rounded to three decimal places, is:
Part 2). The daily sales at a convenience store produce a distribution that is approximately normal with a mean of 1340 and a standard deviation of 125.
In your intermediate calculations, round z-values to two decimal places.
The probability that the sales on a given day at this store are more than$1405, rounded to four decimal places, is:.
The probability that the sales on a given day at this store are less than$1305, rounded to four decimal places, is:.
The probability that the sales on a given day at this store are between$1200 and$1300, rounded to four decimal places, is:.