Answer:
And if we solve for a we got
So the value of height that separates the bottom 20% of data from the top 80% is 23.432.
Step-by-step explanation:
Let X the random variable that represent the heights of a population, and for this case we know the distribution for X is given by:
Where and
For this part we want to find a value a, such that we satisfy this condition:
(a)
(b)
As we can see on the figure attached the z value that satisfy the condition with 0.20 of the area on the left and 0.80 of the area on the right it's z=-0.842
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
So the value of height that separates the bottom 20% of data from the top 80% is 23.432.
Answer:
Allison worked 6 hours lifeguarding and 3 hours washing cars.
Step-by-step explanation:
Let
Number of hours Allison worked lifeguarding last week = x
Number of hours Allison worked washing cars last week = y
1. Last week Allison worked 3 more hours lifeguarding than hours washing cars hours, then
<u>Lifeguarding:</u>
$12 per hour
$12x in x hours.
<u>Washing cars:</u>
$8 pere hour
$8y in y hours.
2. Allison earned a total of $96, hence
You get the system of two equations:
Plot the graphs of these two equations (see attached diagram). These line intersect at point (6,3), so Allison worked 6 hours lifeguarding and 3 hours washing cars.
Answer:
speed of James is: 3.75 miles/hour.
Step-by-step explanation:
We need to find the speed of James in miles per hour(mi/hr)
we know that 1 mile=5280 feet
James takes 120 steps in 1 minute so he will cover 120×60 steps in 1 hour.
i.e. he takes 7200 steps in 1 hour.
also each step of James=2.75 feet
total distance covered by James in 1 hour=2.75×7200 feet=19800 feet
hence speed of James= (distance covered by james in 1 hour)/1 hour
speed of James=3.75 miles/hour.
Thanks!!
Mark me brainliest!
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Answer:
what is the question I don't understand the question so sorry