Help on the last thx!

A student answers a multiple-choice examination question that offers four possible answers. Suppose the probability that the stu

Nitella [24]

Answer: 0.9730

Step-by-step explanation:

Let A be the event of the answer being correct and B be the event of the knew the answer.

Given: $P(A)=0.9$

$P(A^c)=0.1$

$P(B|A^{C})=0.25$

If it is given that the answer is correct , then the probability that he guess the answer $P(B|A)= 1$

By Bayes theorem , we have

$P(A|B)=\dfrac{P(B|A)P(A)}{P(B|A)P(A)+P(C|A^c)P(A^c)}$

$=\dfrac{(1)(0.9)}{(1))(0.9)+(0.25)(0.1)}\\\\=0.972972972973\approx0.9730$

Hence, the student correctly answers a question, the probability that the student really knew the correct answer is 0.9730.

7 0

3 years ago

The salary of two governing bodies in 2008 was $169.3 thousand, and has increased by approximately $4 thousand per year since th

IceJOKER [234]

Answer:

Step-by-step explanation:

Find, find the total increase in salary for 7 years;

If 1 year = $4,000

7 years = ?

=7*4000

=28,000 in total

Original salary = $169,300

Add the total increase in salary to the original salary;

169,300 + 28,000 = 197,300

Therefore, in 7 years, the salary would be $197,300

4 0

3 years ago

HELP ME I DON'T UNDERSTAND IT :(

a_sh-v [17]

Answer:

D

Step-by-step explanation:

A is (-8,8) so you would divide each 8 by 4 because 8 divided by 1/4 so you will have (-2,2)

B is (-8,4) so divide the by 1/4 which would be (-2,1)

C is (4,-4) so divide that and and you get (1,-1)

5 0

3 years ago

The expected number of typographical errors on a page of a certain magazine is .2. What is the probability that an article of 10

Pavel [41]

Answer:

a) The probability that an article of 10 pages contains 0 typographical errors is 0.8187.

b) The probability that an article of 10 pages contains 2 or more typographical errors is 0.0175.

Step-by-step explanation:

Given : The expected number of typographical errors on a page of a certain magazine is 0.2.

To find : What is the probability that an article of 10 pages contains

(a) 0 and (b) 2 or more typographical errors?

Solution :

Applying Poisson distribution,

$N\sim Pois(0.2)$

$P(N=r)=\frac{e^{-np}(np)^r}{r!}$

where, n is the number of words in a page

and p is the probability of every word with typographical errors.

Here, n=10 and E(N)=np=0.2

a) The probability that an article of 10 pages contains 0 typographical errors.

Substitute r=0 in formula,

$P(N=0)=\frac{e^{-0.2}(0.2)^0}{0!}$

$P(N=0)=\frac{e^{-0.2}}{1}$

$P(N=0)=e^{-0.2}$

$P(N=0)=0.8187$

The probability that an article of 10 pages contains 0 typographical errors is 0.8187.

b) The probability that an article of 10 pages contains 2 or more typographical errors.

Substitute $r\geq 2$ in formula,

$P(N\geq 2)=1-P(N$

$P(N\geq 2)=1-[P(N=0)+P(N=1)]$

$P(N\geq 2)=1-[\frac{e^{-0.2}(0.2)^0}{0!}+\frac{e^{-0.2}(0.2)^1}{1!}]$

$P(N\geq 2)=1-[e^{-0.2}+e^{-0.2}(0.2)]$

$P(N\geq 2)=1-[0.8187+0.1637]$

$P(N\geq 2)=1-0.9825$

$P(N\geq 2)=0.0175$

The probability that an article of 10 pages contains 2 or more typographical errors is 0.0175.

6 0

3 years ago

Multiply. Simplify your answer. Write your final result as a whole number or a mixed number.

belka [17]

4³/₄ × 1¹/₂
¹⁹/₄ × ³/₂
⁵⁷/₈
7¹/₈

4 0

3 years ago