a) 
because it is equal to the area of the shaded region between X=4 and X=6, and the probability that X falls within some interval is given by the area under the PDF.
b) 
because the shaded region is a rectangle of height 1/5 (by virtue of X following a uniform distribution over the interval [2, 7], which has length 5).
Answer:
Joe: 3 hrs
Janet: 6hrs
Step-by-step explanation:
joe takes x hours
so in 1 hr he does 1/x of the garden
janet takes 2x hours
so in 1 hr she does 1/(2x) of the garden
In one hour together they do 1/2 of the garden
1/x + 1/(2x) = 1/2
2/(2x) + 1/(2x) = 1/2
3/(2x) = 1/2
Cross multiply
6 = 2x
x = 3
Joe: 3 hrs
Janet: 6hrs
The answer is 2.35714285714!
hope this helps!!
Answer:
1. mean=1.5, median=1.7, mode is 1.8
2. mean=102,median=134, mode=no mode
3. mean=1885,median=2300, mode=2300
Step-by-step explanation:
