Answer:
26.8
Step-by-step explanation:
x/145 = 18.5/100
cross-multiply:
100x = 2682.5
x = 26.8
To find out time interval δt we need to substract initial time from the final time. In this question first number in the coordinates representes time:
δt=50 - 0
δt= 50s
TIme interval is 50s.
Answer:
7
Step-by-step explanation:
This is a Poisson distribution problem with the formula;
P(x;μ) = (e^(-μ)) × (μ^(x))/x!
We are told that the grocer sells three of a certain article per week. Thus;
μ = 3
Now, we want to find out How many of these should he have in stock so that the chance of his running out within a week is less than 0.01.
This means;
P(X > k) < 0.01
This can be rewritten as;
P(X ≤ k) < 0.99
Let's try x = 8
P(8;3) = (e^(-3)) × (3^(8))/8!
P(8;3) = 0.008
But; P(X ≤ 8) = 1 - 0.008 = 0.992
This is more than 0.99 and thus is not the answer
Let's try x = 7
P(7;3) = (e^(-3)) × (3^(7))/7!
P(7;3) = 0.022
But; P(X ≤ 7) = 1 - 0.022 = 0.978
Thus is less than 0.99.
Thus, stock should be 7
There are many ways you can do this. To me, the easiest way is cross multiplying, but since the denominators are the same, there is no need to do that. Also, the fractions are negatives, the one closest to 0 is closer to the surface of the pool
-4/5 = -2/5 in this case -2/5 is closer to the surface of the pool.
Answer: the boy's feet are closer to the surface of the pool
