Answer:
a. 8.66 minutes
Step-by-step explanation:
Since the flight times are uniformly distributed, the standard deviation can be calculated as follows:
Where '<em>b' </em>is the maximum flight time (150 minutes) and '<em>a' </em>is the minimum flight time (120 minutes):
The distribution's standard deviation is 8.66 minutes.
First move the constant to the other side causing it to change sides
4x<-6-6
Then calculate the difference (-6-6)
4x<-12
Now divide both sides by 4
X<-3
Then you are left with your answer:
x<-3
Hope this helps! :3
Answer:
And if we solve for a we got
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".
Solution to the problem
Let X the random variable that represent the hourly rates of a population, and for this case we know the distribution for X is given by:
For this part we want to find a value a, such that we satisfy this condition:
(a)
(b)
Both conditions are equivalent on this case. We can use the z score again in order to find the value a.
As we can see on the figure attached the z value that satisfy the condition with 0.80 of the area on the left and 0.20 of the area on the right it's z=0.842. On this case P(Z<0.842)=0.8 and P(z>0.842)=0.20
If we use condition (b) from previous we have this:
But we know which value of z satisfy the previous equation so then we can do this:
And if we solve for a we got
Answer: 37 fruit pies+42 fruit juices=79 total items
(a) 37*1.65= $61.05
42*1.36= $57.12
(b) Mr Sanchez's class earned more money.
(c) Mr. Sanchez's class earned $3.93 more than Mr. Kelly's class
$61.05-$57.12= $3.93
Step-by-step explanation: