Answer:
20 is x ≥ 25
Step-by-step explanation:
In number 20 you put x is less than or equal to 25 ( x ≤ 25 )
It should be x is greater than or equal to 25 ( x ≥ 25 ) because it says it cannot be less than 25.
All your other answers are correct. Good job.
Answer :
4.25
Step-by-step explanation :
Hope it helped you :)
Answer:
Step-by-step explanation:
1) 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 scores, and for this case we know the distribution for X is given by:
And let
represent the sample mean, the distribution for the sample mean is given by:
On this case
2) Calculate the probability
We want this probability:
The best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
Answer:
The probability density function for the average length of life of the two components is 
Step-by-step explanation:
Exponential distribution:
The exponential probability distribution, with mean m, is described by the following probability density:

In which
is the decay parameter.
Each missile has a length of life governed by the exponential distribution with mean 1 (with measurements in hundreds of hours). Find the probability density function for the average length of life of the two components.
2, each with mean 1 means that 
So the probability density function is:

Answer:
the y value equals 5
Step-by-step explanation:
(x,y)so
plug in 8 for x
5(8)=40
40 -2y=30
subtract 40 from both sides
-2y=-10
divide by -2
y=5