Answer:
Let x = the hours needed for Wanda to catch up to Hector.
Hector has already completed 18 miles. Hector travels at 12 miles per hour.
After x more hours, Hector will travel
18 + 12x miles
Wanda travels at 16 miles per hour. In x hours, she travels
16x miles
If Wanda catches up to Hector, then
16x = 18 + 12x
4x = 18
x = 4.5 hours
Answer: 4 hours, 30 minutes (or 4.5 hours)
Step-by-step explanation:
Complete question:
The manager of a supermarket would like to determine the amount of time that customers wait in a check-out line. He randomly selects 45 customers and records the amount of time from the moment they stand in the back of a line until the moment the cashier scans their first item. He calculates the mean and standard deviation of this sample to be barx = 4.2 minutes and s = 2.0 minutes. If appropriate, find a 90% confidence interval for the true mean time (in minutes) that customers at this supermarket wait in a check-out line
Answer:
(3.699, 4.701)
Step-by-step explanation:
Given:
Sample size, n = 45
Sample mean, x' = 4.2
Standard deviation
= 2.0
Required:
Find a 90% CI for true mean time
First find standard error using the formula:




Standard error = 0.298
Degrees of freedom, df = n - 1 = 45 - 1 = 44
To find t at 90% CI,df = 44:
Level of Significance α= 100% - 90% = 10% = 0.10

Find margin of error using the formula:
M.E = S.E * t
M.E = 0.298 * 1.6802
M.E = 0.500938 ≈ 0.5009
Margin of error = 0.5009
Thus, 90% CI = sample mean ± Margin of error
Lower limit = 4.2 - 0.5009 = 3.699
Upper limit = 4.2 + 0.5009 = 4.7009 ≈ 4.701
Confidence Interval = (3.699, 4.701)
Answer:
1/3
Step-by-step explanation:
Answer:
The function is non-proportional.
Step-by-step explanation:
If the function was proportional, when the number of hours spent riding the bicycle is equal to 0, the total cost of renting the bicycle would also be 0. In other words, the function would be proportional if y=0 when x=0. However, this is not the case.

Plug 0 into the equation as x

When 1 bicycle has been rented for 0 hours, the customer still has to pay 10 dollars just for renting it. When x=0, y=10. This means that the function is non-proportional.
I hope this helps!