Answer:
40
Step-by-step explanation:
Use the Outside Angles Theorem,

Hello, the answer for your question is<span> 12.7.</span>
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.
Answer:

Step-by-step explanation:
Given <u>v</u> = < - 5, 9 > then the magnitude is
| <u>v</u> | =
=
= 
Solve for one of the variables in the first equation (in this case, I will solve for X):
X = Y + 3
Then use that value of X in the second equation to solve for Y:
X + 3Y = 9
(Y + 3) + 3Y = 9
4Y + 3 = 9
4Y = 6
Y = 1.5
Use the value of Y we just found in the X equation we created:
X = Y + 3
X = 1.5 + 3
X = 4.5
Therefore X = 4.5 or 9/2 and Y = 1.5 or 3/2.