Ok, so you know that we can't divide fractions no matter what. The first thing you do is keep the first fraction, then change the divide sign to multiplication ( opposite of division is multi. ) and finallly flip the last fraction to 7/1 .
Here's a video to help you understand that method more ...
https://www.youtube.com/watch?v=uMz4Hause-o
The answer ends up as 6.53333333333
Hope this helps !
1. C. Concave pentagon
2. A. 1620°
b/c (11 - 2) × 180 = 1620
3. B. 165°
b/c (24 - 2) × 180 ÷ 24 = 165
4. A. 160°
b/c (18 - 2) × 180 ÷ 18 = 160
Answer:
2:5:10
Step-by-step explanation:
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.