Answer:
Step-by-step explanation:
a) It is a binomial distribution.
n = 25
p = 0.15
b) mean = np = 25 * 0.15 = 3.75
variance = np(1 - p)
= 25 * 0.15 * (1 - 0.15)
= 3.1875
c) P(X = x) = nCx * px * (1 - p)n - x
P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)
= 25C0 * (0.15)^0 * (0.85)^25 + 25C1 * (0.15)^1 * (0.85)^24 + 25C2 * (0.15)^2 * (0.85)^23 + 25C3 * (0.15)^3 * (0.85)^22 = 0.4711
d) P(X = 3) = 25C3 * (0.15)^3 * (0.85)^22 = 0.2174
Notice that
so that for each power of 2, there is a pattern of period 4. This means that for integers
, each of
,
,
, and
have the same units digit.
We can write
, and since
, it follows that
and
share the same units digits. So the units digit of
is 8.
Answer:
Step-by-step explanation:
A. distribute the X to the X in the parenthesis and you get 2x. Then distribute the X to the -7 in the parenthesis and you get -7x. Combine like terms so that would be 2x-7x and you get -5x.
C. distribute the 6x to the X in the parenthesis and you get 7x. Then distribute the 6x to the 2 in parenthesis and you get 8x. Combine like terms so that would be 7x+8x and you get 15x.
E. Not sure on this one, sorry.
