12.03.2020

# A fair coin is flipped three times. Let X be the number of heads observed. (a) Give both the possible values and probability mass function of X. (b) Find P(X ≥ 1) and P(X > 1). (c) Compute E[X] and V ar(X).

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24.06.2023, solved by verified expert

a)

The possible values are 0, 1, 2 and 3.

The probability mass function of X is:

P(X = 0) = 0.125

P(X = 1) = 0.375

P(X = 2) = 0.375

P(X = 3) = 0.125

b)

,

c) E(X) = 1.5, Var(X) = 0.75

Step-by-step explanation:

For it time the coin is flipped, there are only two possible outcomes. Either it comes up heads, or it comes up tails. Each toss is independent of other tosses. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.

The expected value of the binomial distribution is:

The variance of the binomial distribution is:

A fair coin is flipped three times.

This means that

Fair coin means that it is equally as likely to be heads or tails, so

a) Give both the possible values and probability mass function of X.

The possible values are from 0 to n, so 0, 1, 2 and 3.

The probability mass function is the probability of each outcome. So

(b) Find P(X ≥ 1) and P(X > 1).

(c) Compute E[X] and Var(X).

### Faq

Mathematics

a)

The possible values are 0, 1, 2 and 3.

The probability mass function of X is:

P(X = 0) = 0.125

P(X = 1) = 0.375

P(X = 2) = 0.375

P(X = 3) = 0.125

b)

,

c) E(X) = 1.5, Var(X) = 0.75

Step-by-step explanation:

For it time the coin is flipped, there are only two possible outcomes. Either it comes up heads, or it comes up tails. Each toss is independent of other tosses. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.

The expected value of the binomial distribution is:

The variance of the binomial distribution is:

A fair coin is flipped three times.

This means that

Fair coin means that it is equally as likely to be heads or tails, so

a) Give both the possible values and probability mass function of X.

The possible values are from 0 to n, so 0, 1, 2 and 3.

The probability mass function is the probability of each outcome. So

(b) Find P(X ≥ 1) and P(X > 1).

(c) Compute E[X] and Var(X).

Mathematics
Answer: 440 grams for 1.54 is the better value
Explanation:
Take the price and divide by the number of grams
1.54 / 440 =0.0035 per gram
1.26 / 340 =0.003705882 per gram
0.0035 per gram < 0.003705882 per gram
Mathematics

Cost of 7 gallons=$24.50 Cost of 1 gallon=24.50/7=3.5 Cost of 15 gallons=15*3.5=52.5 Cost of 15 gallons will be$52.5

Mathematics

The answer is in the image

Mathematics

The answer is in the image

Mathematics

The total nom of  code that can be used is equal to 5+3 = 8

Mathematics

y=2x+15

where y=Value of coin

x=Age in years

Value of coin after 19 years=2*19+15

=$53 Therefore, Value after 19 years=$53

Mathematics

F=ma

where F=force

m=mass

a=acceleration

Here,

F=4300

a=3.3m/s2

m=F/a

=4300/3.3

=1303.03kg

Mathematics

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in$1800 sales

Mathematics