Answer:
(a) P(X = 18) = 0.25
(b) P(X > 18) = 0.53
(c) P(X ≤ 18) = 0.47
(d) Mean = 19.76
(e) Variance = 22.2824
(f) Standard deviation = 4.7204
Step-by-step explanation:
We are given that discrete random variable X has the following probability distribution:
X P (x) X * P(x) * P(x)
13 0.22 2.86 169 37.18
18 0.25 4.5 324 81
20 0.20 4 400 80
24 0.17 4.08 576 97.92
27 0.16 4.32 729 116.64
(a) P ( X = 18) = P(x) corresponding to X = 18 i.e. 0.25
Therefore, P(X = 18) = 0.25
(b) P(X > 18) = 1 - P(X = 18) - P(X = 13) = 1 - 0.25 - 0.22 = 0.53
(c) P(X <= 18) = P(X = 13) + P(X = 18) = 0.22 + 0.25 = 0.47
(d) Mean of X, = ∑X * P(x) ÷ ∑P(x) = (2.86 + 4.5 + 4 + 4.08 + 4.32) ÷ 1
= 19.76
(e) Variance of X, = ∑ * P(x) -
= 412.74 - = 22.2824
(f) Standard deviation of X, = = = 4.7204 .
The probabilities for the given X values are calculated by summing the relevant given probabilities. The mean of X is computed as a weighted average, and the variance and standard deviation are calculated using formula involving the mean and the individual probabilities.
The probability P(18) is given as 0.25 according to the distribution. The probability P(X > 18) is the sum of the probabilities for all x > 18, so we add the probabilities for x=20, x=24, and x=27, giving us 0.20 + 0.17 + 0.16 = 0.53. The probability P(X ≤ 18) includes x=18 and any values less than 18. As 18 is the lowest value given, P(X ≤ 18) is just P(18), or 0.25.
The mean μ of X is the expected value of X, computed as Σ(xP(x)). That gives us (13*0.22) + (18*0.25) + (20*0.20) + (24*0.17) + (27*0.16) = 2.86 + 4.5 + 4 + 4.08 + 4.32 = 19.76.
The variance σ 2 of X is computed as Σ [ (x - μ)^2 * P(x) ]. That gives us [(13-19.76)^2 * 0.22] + [(18-19.76)^2 * 0.25] + [(20-19.76)^2 * 0.20] + [(24-19.76)^2 * 0.17] + [(27-19.76)^2 * 0.16] = 21.61. The standard deviation σ of X is the sqrt(σ^2) = sqrt(21.61) = 4.65.
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Answer:
a. x = 8
b. m<B = 140
Step-by-step explanation:
a.
m<A = m<B
40 = 5x
x = 8
b.
m<A + m<B = 180
m<B = 180 - m<A
m<B = 180 - 40
m<B = 140
Answer:
a = 60
Step-by-step explanation:
Since it is a quadrilateral, the sum of interior angles is equal to 360°. Now you have to create an equation to solve this question. To create an equation, you have to add all the interior angles to 360°.
The equation would be 2a°+a°+a°+2a° = 360°.
Then you would simplify it to 6a° = 360.
You would divide 6 on both sides to get to a° = 60.
Therefore, the value of a is 60.
Hope this helped! If not, please let me know! <3
Answer:
Quadratic function
Step-by-step explanation:
Hope this helps you. Have a great day and I hope to get a brainliest.
Answer:
1. 15 to 21 = 21 - 15 / 15 = 0.4*100% = 40%
2. 12 teachers to 48 teachers = 48 - 12/48 = 0.75 * 100% = 75%
3. 80 pencil to 120 pencil = 120 - 80 / 80 = 0.5*100% = 50%
4. 40 cans to 70 cans = 70 - 40 / 70 = 0.43 * 100% = 43%
Answer:
For the hole family it will cost 96.5$
Step-by-step explanation:
There are two adults, $25 each. 2×25=50
There are 3 children, 15.50 each. So you do 3×15.50= 46.5
To find the total cost add them both.
46.5+50= 96.5
Answer:
The total cost is $96.5