The average class size this semester in the business school of a particular university is 16 students with a standard deviation of 3.9 students. The z-score for a class with 21 students is .

1.28

Step-by-step explanation:

We are given;

Population mean; μ = 16

Population standard deviation; σ = 3.9

Sample mean; x' = 21

Formula for z-score is;

z = (x' - μ)/σ

z = (21 - 16)/3.9

z = 1.28

answer: idk

step-by-step explanation:

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!