Huh what about the photo you gotta b
Number of days Val rented the bicycle is 8
<h3><u>Solution:</u></h3>
Given that val paid a flat rental fee of $55.00 plus $8.50 each day
The total cost was $123
To find: number of days she rented the bicycle
Let "a" be the number of days she rented the bicycle
Rental fee = $55.00
Fee for one day = $ 8.50
So total cost is equal to rental fee and fee for "a" days
Total cost = rental fee + (number of days she rented the bicycle x Fee for one day)


123 - 55 = 8.50a
8.50a = 68

Thus number of days she rented the bicycle is 8
Why not look up "standard deviation" yourself, to be sure? But yes, the std. dev. is the sqrt of the variance.