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
The shortest distance between the tip of the cone and its rim exits 51.11cm.
<h3>
What is the shortest distance between the tip of the cone and its rim?</h3>
If you draw a line along the middle of the cone, you'd finish up with two right triangles and the line even bisects the angle between the sloping sides. The shortest distance between the tip of the cone and its rim exists in the hypotenuse of a right triangle with one angle calculating 38.5°. So, utilizing trigonometry and allowing x as the measurement of the shortest distance between the tip of the cone and its rim.
Cos 38.5 = 40 / x
Solving the value of x, we get
Multiply both sides by x


Divide both sides by 

simplifying the above equation, we get

x = 51.11cm
The shortest distance between the tip of the cone and its rim exits 51.11cm.
To learn more about right triangles refer to:
brainly.com/question/12111621
#SPJ9
Answer:I dont belive i know
Step-by-step explanation:
7) 2-9= -7 because, if you have two cookies and promised nine friends cookies, you would still owe 7 friends cookies or -7
8) -3 - (-4)= 1 because you owe 3 friends cookies, then you get 4 cookies and have one left over
9) 11 - (-12)= 23 because a negative plus a negative is a positive
Answer:
ABC
Step-by-step explanation:
78 > 56
78 > 46
56 > 46
78, 56, 46