Answer:
you answer should be b
Step-by-step explanation:
I am not 100% sure
Answer:
61 commuters must be randomly selected to estimate the mean driving time of Chicago commuters.
Step-by-step explanation:
Given : We want 95% confidence that the sample mean is within 3 minutes of the population mean, and the population standard deviation is known to be 12 minutes.
To find : How many commuters must be randomly selected to estimate the mean driving time of Chicago commuters?
Solution :
At 95% confidence the z-value is z=1.96
The sample mean is within 3 minutes of the population mean i.e. margin of error is E=3 minutes
The population standard deviation is s=12 minutes
n is the number of sample
The formula of margin of error is given by,

Substitute the value in the formula,




Squaring both side,

Therefore, 61 commuters must be randomly selected to estimate the mean driving time of Chicago commuters.
4x / 5 = 1 / 3 ( 2x - 15 )
4x / 5= ( 2x - 15 ) / 3
4x × 3 = 5 ( 2x - 15 )
12x = 10x - 75
12x - 10x = - 75
2x = - 75
x = - 75 / 2
x = - 37.5
Factors of 121 are; 1,11, and 121. so it would be D.
B. D represents the amount of dimes and q represents the amount of quarters so that equals 20 coins total. 0.25q is the amount of quarters multiples by their cost, when added to 0.1d it equals 4.25.