Answer:
E(X) = 6
Var(X) = 3.394
Step-by-step explanation:
Let X represent the number of carp caught out of the 20 fishes caught. Now, if we are to assume that each
of the (100, 20) ways to catch the 20 fishes will be equally likely.
Thus, we can say that X fulfills a hypergeometric
distribution with parameters as follows;
n = 20, N = 100, k = 30
Formula for expected mean value in hypergeometric distribution is;
E(X) = nk/N
E(X) = (20 × 30)/100
E(X) = 6
Formula for variance is;
Var(X) = (nk/N) × [((n - 1)(k - 1)/(N-1))) + (1 - nk/N)]
Var(X) = ((20 × 30)/100) × [((20 - 1)(30 - 1)/(100 - 1)) + (1 - (20 × 30/100)]
Var(X) = 6 × 0.5657
Var(X) = 3.394
Hello,
A cubic polynomial with -2,1,2 as roots is
f(x)=k*(x+2)(x+1)*(x-2)=k(x²-4)(x+1)=k(x^3+x²-4x-4)
Looking the answers ==>k=1
==>Answer A
Answer:
Both lights flash at 1:00
Step-by-step explanation:
they flash together every 2*7=14 minutes
in 60 minutes there are 4*14=56 minutes
they flash together at 1:56
more minutes brings you to 2:00
they flash together at 2:10 (4+10=14)
that leaves 50 minutes left in the hour
they flash three times which uses up 42 minutes
this brings you to 2:52 (10+42=52)
8 more minutes brings you to 3:00
in 6 more minutes (8+6=14) it will be 3:06 and they will flash together
A. I would estimate that 7 in of the ribbon
B. the estimate would be high because the longer the ribbon is the more of the ribbon would have to be cut.
C. 11.7 - 5.25 = 6.45 iris has to cut 6.45 off the longer ribbon for the ribbons to be the same length.
