Answer:
b. The values X and Y are independent therefore, the mean is 34 seconds and the standard deviation is 50 seconds
Step-by-step explanation:
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Before the training, the mean running time for the students to run a mile was 402 seconds with standard deviation 40 seconds.
This means that 
After completing the program, the mean running time for the students to run a mile was 368 seconds with standard deviation 30 seconds.
This means that 
Which of the following is true about the distribution of X-Y?
They are independent, so:
This means that the correct answer is given by option b.
One company wants $10 per 3.5 hours, so they want 10 / 3.5 ≈ 2,86 dollars per hour (after rounding to the closest hundreths).
Second company wants $1.25 per half an hour, so they want 2 * 1,25 = 2,50 dollars per hour.
The unit rate is 2,86:2,50
Answer:
The answer is 24.
Step-by-step explanation:
Step-by-step explanation:
to be honest I'm not sure how to do
Comment
Answer:
1.5 kg of pepper cheddar cheese and 4.5 kg of Pennsylvania jack was used in the mixture.
Step-by-step explanation:
Pepper Cheddar cheese = $15 per kilogram
Pennsylvania jack = $11 per kilogram
The cheese sampler includes a Pepper Cheddar cheese and a Pennsylvania jack that cost $15 per kilogram and $11 per kilogram respectively.
The mixture = 6 kg
Let
a = kg of the pepper cheddar cheese
b = kg of the Pennsylvania jack
a + b = 6............(i)
Rate
15a + 11b/6 = 12
15a + 11b = 72.............(ii)
Combine the equation
a + b = 6............(i)
15a + 11b = 72.............(ii)
a = 6 - b
15(6 - b) + 11b = 72
90 - 15b + 11b = 72
90 - 72 = 15b - 11b
18 = 4b
divide both sides by 4
b = 18/4
b = 4.5 kg
insert the value of b in equation (i)
a + b = 6............(i)
a = 6 - 4.5
a = 1.5 kg
1.5 kg of pepper cheddar cheese and 4.5 kg of Pennsylvania jack was used in the mixture.
