In a recent survey of high school students, it was found that the average amount of money spent on entertainment each week was normally distributed with a mean of $52.30. suppose you are told that there is an 80% probability that a randomly-selected student spends somewhere between $49.74 and $54.86. what is the standard deviation of the amount of money spent by high school students monthly?

Std dev = 0.50

Step-by-step explanation:

Given that in a recent survey of high school students, it was found that the average amount of money spent on entertainment each week was normally distributed with a mean of $52.30.

Also given that

For 49.74 we have x-mean =

For 54.86 we have x-mean =

Hence we have

he standard deviation of the amount of money spent by high school students monthly=0.50

e^-kt = n/n0 = 0.79  

-kt = ln 0.79  

t = - ln 0.79/0.0001  

= 2357 years

step-by-step explanation:

12r - 8 - 12

you have to combine like terms. below i have bolded the like terms:

12r - 8 - 12

together it combines to:

12r - 20

hope this !