The cost of renting a game at the video store can be described by the function y=5x+4 , where y is the total cost and x is the number of days. If Justin has $18 to spend, what is the maximum number of days that he can rent a game if tax is not considered

2 days

Step-by-step explanation:

Use the given formula

y = 5x + 4

The information:

y is the money spent

x is the number of days

It is known that Justin spent $18

so now just substitute in that value

$18 = 5x + 4

and simplfiy by inverse operations

18 = 5x + 4

-4        -4

14 = 5x

/5    /5

2.8 = x

As per this problem, one can infer that renting a game is done by days, and will be charged in days, hence renting a game for 0.8 days is pointless

meaning that the final answer is 2 full days

ruth is 6 years old

step-by-step explanation:

6 + 24 = 30,   so 6/30 = .2  

if you do 1/5 it also equals .2, so that is the answer.

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.