To solve for x, we will begin by using the distributive property
6x - 2(x + 4) = 12
6x - 2x - 8 = 12
(always remember to sort your negatives!)
Add like terms
4x - 8 = 12
Add 8 to both sides
4x = 20
Divide both sides by 4
x = 5
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;


Answer:
D
Step-by-step explanation:
There is a 100% chance that if she picks 3 disk, they are all DVD's since they are all DVD's.
Answer:
D. (x-2)(x-4)
Step-by-step explanation:
The graph cross the x-axis in points with x-coordinates of 2 and 4
then 2 and 4 are roots of x² - 6x + 8.