Answer:
0.27
Step-by-step explanation:
We know that p0 + p1 = 2 5 = 0.4
p0 + p1 + p2 + p3 + p4 + p5 = 1.
k = p0 − p1 = p1 − p2 = p2 − p3 = p3 − p4 = p4 − p5 .
Then p1 = p0 − k, p2 = p1 − k = p0 − k − k = p0 − 2k, etc.,
so that pn = p0 − nk for 1 ≤ n ≤ 5.
Thus p0 + ( p0 − k) + ( p0 − 2k) +…+ ( p0 − 5k) = 6 p0 − 15k = 1.
Also 40% = 0.4 = p0 + p1 = p0 + ( p0 − k) = 2 p0 − k.
This results in the following equations:
6 p0 −15k = 1,
2 p0 − k = 0.4,
Solving, the above: k = 1/60 and p0 = 25 /120 .
Therefore: p4 + p5 = ( p0 − 4k) + ( p0 − 5k)
= 17 /120 + 15 /120
= 32 /120 = 0.2667 ~ 0.27
