How many different simple random samples of size 4 from a population size 46

This is one single number. The number is slightly larger than 163 thousand.

Explanation:

Consider four slots labeled A,B,C,D

We have

There's a countdown going on (46,45,44,43) when filling up the slots. This countdown is because we cannot reselect any specific person for multiple slots at the same time.

If order mattered, then we'd have 46*45*44*43 = 3,916,440 permutations possible.

However, order doesn't matter. For any group of 4 people, there are 4! = 4*3*2*1 = 24 ways to arrange them. So we must divide the previous result over 24 to get (3,916,440)/24 = 163,185

This means there are 163,185 different combinations and this is the number of possible samples of size 4 from a population of 46 people. The order of any sample doesn't matter.

the answer would be 1 1/72

step-by-step explanation:

you can rewrite the equation by separating the parts and then solving individually:

10-9=1

1/8 - 1/9=

find l c d and then combine:

1 1/72

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240