PLEASEEEEEE HELP ME WITH THIS PLEASE

Solve the riddle i am 6 more than 2 times 9 what number am i now make up your own riddle for the number 68

Lesechka [4]

The riddle answer is 24.

A riddle for the number 68 is: 12 more than 14 times 4

5 0

3 years ago

Read 2 more answers

The probability that two people have the same birthday in a room of 20 people is about 41.1%. It turns out that

salantis [7]

Answer:

a) Let X the random variable of interest, on this case we know that:

$X \sim Binom(n=20, p=0.411)$

This random variable represent that two people have the same birthday in just one classroom

b) We can find first the probability that one or more pairs of people share a birthday in ONE class. And we can do this:

$P(X\geq 1 ) = 1-P(X$

And we can find the individual probability:

$P(X=0) = (20C0) (0.411)^0 (1-0.411)^{20-0}=0.0000253$

And then:

$P(X\geq 1 ) = 1-P(X$

And since we want the probability in the 3 classes we can assume independence and we got:

$P= 0.99997^3 = 0.9992$

So then the probability that one or more pairs of people share a birthday in your three classes is approximately 0.9992

Step-by-step explanation:

Previous concepts

A Bernoulli trial is "a random experiment with exactly two possible outcomes, "success" and "failure", in which the probability of success is the same every time the experiment is conducted". And this experiment is a particular case of the binomial experiment.

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

Solution to the problem

Part a

Let X the random variable of interest, on this case we know that:

$X \sim Binom(n=20, p=0.411)$

This random variable represent that two people have the same birthday in just one classroom

Part b

We can find first the probability that one or more pairs of people share a birthday in ONE class. And we can do this:

$P(X\geq 1 ) = 1-P(X$

And we can find the individual probability:

$P(X=0) = (20C0) (0.411)^0 (1-0.411)^{20-0}=0.0000253$

And then:

$P(X\geq 1 ) = 1-P(X$

And since we want the probability in the 3 classes we can assume independence and we got:

$P= 0.99997^3 = 0.9992$

So then the probability that one or more pairs of people share a birthday in your three classes is approximately 0.9992

4 0

4 years ago

Can someone explain the steps to finding the perimeter of a semi-circle? I didn't really understand it during class. Thanks

andriy [413]

We know that the perimeter of a cylinder is 2πr we will find it as we do always. The perimeter will be :
2 pi r
= 2 pi * 20
= 40 pi
Because it says rounded to the nearest tenth the answer will be : 125.6 cm^3
Because we have a half of a cylinder we will just divide the answer we got by 2:
125.6cm^3 /2 =62.8
The answer is 62.8 cm^3

6 0

3 years ago

Can someone help me find the volume please

umka2103 [35]

Answer:

See below.

Step-by-step explanation:

The figure is a cone. The formula for the volume of a cone is:

$V=\frac{1}{3}\pi r^2h$