Answer:
12 inches by 21 inches
Step-by-step
Let's start with the 8 feet
for every 2 feet add three inches you get a total of 12 inches
same for the 14 feet, you get 21 inches
Answer:
10. 27 shoes
11. No, both are 18, they are equal
12. 96 dogs
13. 125 students
14. 600 students
15. 50 tulips
16. 70 cars
17. Rory divided the percentage by the number (#/%=#)
Step-by-step explanation:
To find a percentage of somethin, multiply the number by the percent
(54 shoes x 50% (0.50) = 27 shoes)
To find the original number, divide the new number by the percentage
(25 students/20% (0.20) = 125 students)
Answer:
3. 122.025
4. 469.2
Step-by-step explanation:
16.27/2 =8.135
8.135*15= 122.025
11.73 divided by 1/2= 23.46
23.46*20=469.2
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.