According to the Internal Revenue Service, the average income tax refund for the 2018 tax year was $2,780. Assume the refund the per person follows the normal probability distribution with a standard deviation of $950. What is the probability that a randomly selected tax return refund from the 2018 tax year will be more than $3,000
a) What is the probability that a randomly selected tac return will be
1) more than $2000?
2) between $1600 and $2500?
3) between $3200 and $4000?
b) Confirm the answers using an excel sheet.
c) What refund amount represents the 35th percentile of tax returns?

nlgqer

step-by-step

sorry

step-by-step explanation:

sorry, but im pretty sure its a now that i look at it

unless you made a typo, the answers are both a and c.

step-by-step explanation:

1.5/3 is .5 whereas 3/9 is .3333333 not proportional

22/33 is .66666 and 4/6 is also .66666 proportional

2/4 is .5 whereas 142/213 is .66666 not proportional

14/7 is 2 and 7/3.5 is also 2 proportional

you could've also checked it by doing this simple division:

if the larger fraction divides with the smaller fraction to equal 1, it is proportional. so let me show you what i mean:

when i divide 22/33 by 4/6 i get 1, so we know it is proportional, and it is the same with 14/7 and 7/3.5. now if i divide 3/9 by 1.5/3 i get .66666 so therefore we know it is not proportional.

there are many ways to do this so i wanted to show you some possible ways.