Answer:
0.36427
Step-by-step explanation:
Mean = λ = 18 messages per hour
P(X = x) = (e^-λ)(λ⁻ˣ)/x!
P(X ≤ x) = Σ (e^-λ)(λ⁻ˣ)/x! (Summation From 0 to x)
But the probability required is that the messages thay come in an hour is between 15 and 20, that is, P(15 < X < 20)
P(15 < X < 20) = P(X < 20) - P(X ≤ 15)
These probabilities will be evaluated using a cumulative frequency calculator.
P(X < 20) = 0.65092
P(X ≤ 15) = poissoncdf(18, 15) = 0.28665
P(15 < X < 20) = P(X < 20) - P(X ≤ 15) = 0.65092 - 0.28665 = 0.36427.
You can use the Poisson distribution calculator here
https://stattrek.com/online-calculator/poisson.aspx
Answer:
Amrita's number is 6
Step-by-step explanation:
x Double the unknown number
2x Add 9
2x + 9 Divide the answer by 3
2/3x + 3 Subtract 1
2/3x + 2 Set this equal to the original number
2/3x + 2 = x
-2/3x -2/3x Subtract 2/3x from both sides
2 = 1/3x Multiply both sides by 3
6 = x
Answer:
x=4 Inch
Step-by-step explanation:
Length of the Square = 24 Inches
If a Square of Length x cm is cut out from each corner
Length of the Box = 24-x-x=(24-2x) Inches
Width of the Box =24-x-x=(24-2x) Inches
Height of the box = x inches
Volume of a Cuboid = Length X Width X Height
V(x)= x(24-2x)(24-2x)
Simplifying
V(x)=4x(12-x)(12-x)
To determine the value of x at which V is largest, we take the derivative of V(x) and solve for the critical points.
V(x)=4x(12-x)(12-x)

Set the derivative equal to zero to obtain the critical points

x cannot be equal to 12 as it divides the length of the square cardboard into exactly two equal parts.
When x=4
V(4)=4*4(12-4)(12-4)=16*8*8=1024 Cubic Inches
When x=4 Inch, the volume, V of the open box is largest.
You do nine divided by fifteen which =$0.6
The x intercept would be -2
and the y intercept would be 21