Answer:
a) 
b) 
Step-by-step explanation:
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".
Let X the random variable that represent the interpupillary distance (the distance between the pupils of the left and right eyes) of a population, and for this case we know the distribution for X is given by:
Where
and
And let
represent the sample mean, the distribution for the sample mean is given by:
On this case
Part a
(a) What is the probability that the waiting time will exceed 20 minutes, given that it has exceeded 15 minutes?

We can find the inidivual probabilities like this:


And then we can replace

Part b
(b) What is the probability that the waiting time will exceed 25 minutes, given that it has exceeded 18 minutes?

We can find the inidivual probabilities like this:


And then we can replace

5x-3x-2=13
2x-2=13
2x=15
x=7.5
Answer:
IT would be a because the x and y represents the humans
Step-by-step explanation:
Answer:
400 calories in 4 cups of cereal.
Step-by-step explanation:
The unit rate is how many calories are in 1 cup of cereal.
Set up a proportion:
Cross multiply and solve:
There are 100 calories per cup of cereal.
To get the calories in 4 cups of cereal, simply multiply the unit rate of 100cals/cup by 4.
There are 400 calories in 4 cups of cereal.
Answer:
The answer to your question is the last choice
Step-by-step explanation:
Data
Vertex = (-3 , -2)
From the picture, we know that it is a vertical parabola that opens downwards.
Formula for this parabola
-(x - h)² = 4p(y - k)
- if p = 1/4, then 4p = 4(1/4) = 1 and the equation is
- (x - h)² = y - k
The equation is negative because it opens downwards.
- Substitution
-(x + 3)² = y + 2
- Solve for y
y = -(x + 3)² - 2