The probability density function of X, the lifetime of a certain type of electronic device (measured in hours), is given by $$f ( x ) = \left{ \begin{array} { l l } { \frac { 10 } { x ^ { 2 } } } & { x > 10 } \ { 0 } & { x \leq 10 } \end{array} \right.$$ (a) Find P{X>20}. (b) What is the cumulative distribution function of X? (c) What is the probability that, of 6 such types of devices, at least 3 will function for at least 15 hours? What assumptions are you making? (d) Let Y be the lifetime of the same device measured in minutes. What is the probability density function of Y ?

answer:   n ≤ -3 or n < -5

step-by-step explanation:

-5 + 2n ≥ -11

+5             +5

2n ≥ -6

2/2 ≤ -6/2

n ≤ -3

-6 - 10n > 44

+6           +6

-10n > 50

-10/-10 50/-10

n < -5

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.