Answer:
a) P(X≥6) = 0.9614
b) P(7≤ X ≤9) = 0.628
c) P(X≤5) = 0.0386
Step-by-step explanation:
This can be solved using the binomial distribution formula:
P(X=x) = ⁿCₓ pˣ qⁿ⁻ˣ
Where p = probability of success
q = probability of failure = 1-p
n = number of trials
x = number of successful trials
We have p = 70% = 0.7
n = 12
a) Find the probability that the number who disapprove of smoking pot daily is no less than 6 i.e. P(X≥6). This can be calculated as:
P(X≥6) = 1 - P(X<6)
= 1 - [P(X=0) + P(X=1) + P(X=2) + P(X=3) + P(X=4) + P(X=5)]
= 1 - [¹²C₀ (0.7)⁰(0.3)¹² + ¹²C₁ (0.7)¹(0.3)¹¹ + ¹²C₂ (0.7)²(0.3)¹⁰ + ¹²C₃ (0.7)³(0.3)⁹ + ¹²C₄ (0.7)⁴(0.3)⁸ + ¹²C₅ (0.7)⁵(0.3)⁷]
= 1 - (0.000000531 + 0.0000148 + 0.0001909 + 0.00148 + 0.00779 + 0.02911)
= 1 - 0.0386
P(X≥6) = 0.9614
b) P(7≤ X ≤9) = P(X=7) + P(X=8) + P(X=9)
= ¹²C₇ (0.7)⁷(0.3)¹²⁻⁷ + ¹²C₈ (0.7)⁸(0.3)¹²⁻⁸ + ¹²C₉ (0.7)⁹(0.3)¹²⁻⁹
= 0.158 + 0.231 + 0.239
P(7≤ X ≤9) = 0.628
c) P(X≤5) = P(X=0) + P(X=1) + P(X=2) + P(X=3) + P(X=4) + P(X=5)
= ¹²C₀ (0.7)⁰(0.3)¹² + ¹²C₁ (0.7)¹(0.3)¹¹ + ¹²C₂ (0.7)²(0.3)¹⁰ + ¹²C₃ (0.7)³(0.3)⁹ + ¹²C₄ (0.7)⁴(0.3)⁸ + ¹²C₅ (0.7)⁵(0.3)⁷
P(X≤5) = 0.0386
Step-by-step explanation:
f(x) = (x-2)/(3x+3). Let y = f(x).
Then y = (x-2)/(3x+3).
y(3x+3) = x - 2
3xy + 3y = x - 2
3xy - x = -3y - 2
x(3y-1) = -(3y+2)
x = -(3y+2)/(3y-1)
Hence, the inverse of f(x) is -(3x+2)/(3x-1).
Answer:
D. 21
Step-by-step explanation:
28-21=7
28-7=21
(-1/4)x + 2 = 8
Multiply all terms by 4.
(-1)x + 8 = 32
Simplify.
-x + 8 = 32
Subtract 8 from both sides.
-x = 24
Multiply both sides by -1.
x = -24.
<h3>The value of x is equal to -24.</h3>
-1/4(-24) + 2 = 8
