Answer:
Let X the random variable that represent the delivery times of a population, and for this case we know the distribution for X is given by:
Where
and
Since the distribution of X is normal then we know that the distribution for the sample mean
is given by:
And we have;


Step-by-step explanation:
Assuming this question: The delivery times for all food orders at a fast-food restaurant during the lunch hour are normally distributed with a mean of 14.7 minutes and a standard deviation of 3.7 minutes. Let R be the mean delivery time for a random sample of 40 orders at this restaurant. Calculate the mean and standard deviation of
Round your answers to two decimal places.
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the delivery times of a population, and for this case we know the distribution for X is given by:
Where
and
Since the distribution of X is normal then we know that the distribution for the sample mean
is given by:
And we have;


Given:
A line contains the points R(-1, 8), S(1, 4) and T(6, y).
To find:
The value of y.
Solution:
Three points are collinear if:

A line contains the points R(-1, 8), S(1, 4) and T(6, y). It means, these points are collinear.



Subtract 12 from both sides.

Divide both sides by 2.


Therefore, the value of y is -6.
Answer:
1036 students
Step-by-step explanation:
Let the number of students at West High be "w" and the number of students at East High be "e"
West High population is 250 FEWER than TWICE of East High, we can write:
w = 2e - 250
Total students in both schools is 2858, so we can write 2nd equation as:
e + w = 2858
We can replace 1st equation in 2nd to get an equation in e, and find "e":
e + w = 2858
e + (2e - 250) = 2858
3e - 250 = 2858
3e = 2858 + 250
3e = 3108
e = 3108/3
e = 1036
Hence,
number of students attending East High School = 1036 students
I think you need to retype this one. The formatting makes this question difficult to understand.