Answer:
The volume of the hollow ball will be equal to the difference between the volume of a sphere with the outer radius and the volume of a sphere with the inner radius.
Remember that the volume of a sphere of radius R is given by:
V = (4/3)*pi*R^3
where pi = 3.14
Then if R is the outer radius, and r is the inner radius, the volume of the hollow ball is:
V = (4/3)*pi*( R^3 - r^3)
In this case, we have:
R = 200m
r = 100m
Then the volume of the hollow ball is:
V = (4/3)*3.14*( (200m)^3 - (100m)^3)
V = 29,306,666.67 m^3
Now, if this hollow ball is made of iron, we want to find the mass.
Remember the relation:
Mass = Density*Volume.
We know that the density of the iron is:
D = 7300 kg/m^3
Then the mass of this hollow ball is:
M = (7300 kg/m^3)*(29,306,666.67 m^3) = 213,938,666,666.6 kg
The oil prospector drills wells with a success probability of 0.15. The probability of finding the first productive well in the third attempt is 0.108375 and the probability that the prospector fails to find productive well in the first 5 attempts is 0.26724 or 26.724%
Let Y be the number of drilling trials on which the prospector will find the first productive well. As Y is a geometric random variable with p=0.15 where p is the probability of being successful on any drilling. Let q = 1- p be the probability of being unsuccessful in drilling a well. q = 1 - 0.15 = 0.85
The probability that the first productive well is found on the third attempt is when outcomes are independent
P(Y=3) = q * q * p = 0.85^2* 0.15 = 0.108375
We want to find the probability that 5 wells are drilled and not a productive one is found. That is we need to find p(Y>5). Y is a binomial random variable with several wells drilled at most as n. Given n=5 and p=0.15, q = 0.85
We know the geometric probability is p(y) = p
Then corresponding probabilities are added
p(Y≤ 5 ) = p(0) + p(1) +p(2) + p(3) +p(4) +p(5)= 0.73276
Using the complement rule:
p(Y>5) = 1 - p(Y≤5) = 1- 0.73276 = 0.26724 = 26.724 %
Problem on finding the probability of success on rolling a die:
brainly.com/question/13012531
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Answer:
ok this means that adding 1 to x equals 19
so if we subtract one from 19
19-1=18
so x=18
Hope This Helps!!!
Use the two lines to make them parallel
The '40 years' is not part of the question. It's just there to prove that
'2% each year' has been the experience for the past 40 years, so it's
a good number to use for the rate of growth, past or future.
So, at any number of years 'Q' after the beginning of "this period",
the population was or will be
Pop = (220,000) (1.02)^Q power.
(This equation is familiar from all of the bank-interest problems
the student has done in past math classes.)
In 10 years after the beginning of "this period",
Pop = (220,000) (1.02)¹⁰ = <em>243,800 </em>(or any reasonably close number)