Answer:
a) 3/64 = 0.046 (4.6%)
b) 63/64 = 0.9843 (98.43%)
c) 1/64 = 0.015 (1.5%)
d) 1/4 = 0.25 (25%)
Step-by-step explanation:
in order to verify that the f(x) is a probability mass function , then it should comply the requirement that the sum of probabilities over the entire space of x is equal to 1. Then
∑f(x)*Δx = 1
if f(x)=(3/4)(1/4)^x , x = 0, 1, 2, ...
then Δx=1 and
∑f(x) = (3/4)∑(1/4)^x = (3/4)* [ 1/(1-1/4)] = (3/4)*(4/3) = 1
then f represents a probability mass function
a) P(X = 2)= f(x=2) = (3/4)(1/4)^2 = 3/64 = 0.046 (4.6%)
b) P(X ≤ 2) = ∑f(x) = f(x=0)+ f(x=1) + f(x=2) = (3/4) + (3/4)(1/4) + 3/64 = 63/64 = 0.9843 (98.43%)
c) P(X > 2)= 1- P(X ≤ 2) = 1 - 63/64 = 1/64 = 0.015 (1.5%)
d) P(X ≥ 1) = 1 - P(X < 1) = 1 - f(x=0) = 1- 3/4 = 1/4 = 0.25 (25%)
Answer: 7 × ( 3^n - 1 )
Step-by-step explanation:
This is a geometric progression which has its nth term to be
Tn = ar^n- 1. Now from the question given, the sequence are 7, 21, 63, 189. This is an example of a finite sequence, To find the common ratio, you divide the second term by the first term. So
r = 21/7
= 3. , a = 7
Now to find the nth term put the values in the formula above.
Tn =ar^n-1
= 7(3)^n - 1)
= 7 × ( 3^n - 1 ).
Note, it is not 21^n - 1.
Combine like terms:
n^3 + 20n^ + 10n^2
= n^3 + 30n^
Divide:
=n^3 + 30n^2/10n^2
Factor:
=n^2n + 30n^2
=n^(n + 30)
= 2^2(n + 30)/10n^2
Cancel the common factor n^2:
=n + 10/10
Answer:answer is 28.00065 hope this helps
Step-by-step explanation:
