How to solve q =r/2(s+t) for t

Probability extension: Jerry did only 5 problems of one assignment. What is the probability that the problems he did comprised t

zimovet [89]

Answer:

(b) 1/792

Step-by-step explanation:

The complete question is;

Counting: Grading One professor grades homework by randomly choosing 5 out of 12 homework problems to grade.

(a) How many different groups of 5 problems can be chosen from the 12

problems?

(b)Probability extension: Jerry did only 5 problems of one assignment. What is the probability that the problems he did comprised the group that was selected to be graded?

In (a)

Apply the formula

$\frac{n!}{(n-r)!(r!)}$

where n=12 and r=5

substitute values

$=\frac{12!}{(12-5)!(5!)} \\\\\\=\frac{12!}{(7!)(5!)} \\\\\\=\frac{12*11*10*9*8}{5*4*3*2*1} \\\\\\=\frac{95040}{120} \\\\\\=792$

In (b)

If Jerry did only 5 problems of one assignment then the probability will be

$\frac{5}{12} *\frac{4}{11} *\frac{3}{10} *\frac{2}{9} *\frac{1}{8} =\frac{1}{792}$

4 0

2 years ago

You are given a graph that models a ball being thrown in the air. The vertical axis is the height of the ball from the ground an

aalyn [17]

The graph is going to be all three, because when you throw the ball it goes higher, then constant, then comes back down. It has a maximum point because you can only throw the ball so high up, then it starts to come back down.

If this helped then please give brainliest answer, rate, and thank!

6 0

2 years ago

Which correctly describes a cross section of the cube below? Check all that apply.

dmitriy555 [2]

Answer:

A cross section parallel to the base is a square measuring 4 cm by 4 cm.

A cross section perpendicular to the base through the midpoints of opposite sides is a square measuring 4 cm by 4 cm.

A cross section that passes through the entire bottom front edge and the entire top back edge is a rectangle measuring 4 cm by greater than 4 cm.

Step-by-step explanation:

Cross sections parallel and Perpendicular to the base are squares 4 × 4

The diagonal cross section will be a rectangle with base 4 and height

sqrt(4² + 4²) = 4sqrt(2) > 4

7 0

2 years ago

Read 2 more answers

An certain brand of upright freezer is available in three different rated capacities: 16 ft3, 18 ft3, and 20 ft3. Let X = the ra

ruslelena [56]

Answer:

$E(X)=16\cdot 0.3+18\cdot 0.1+20\cdot 0.6=18.6$

$E(X^2)=16^2\cdot 0.3+18^2\cdot 0.1+20^2\cdot 0.6=349.2$

$V(X) = E(X^2)-[E(X)]^2=349.2-(18.6)^2=3.24$

The expected price paid by the next customer to buy a freezer is $466

Step-by-step explanation:

From the information given we know the probability mass function (pmf) of random variable X.

$\left|\begin{array}{c|ccc}x&16&18&20\\p(x)&0.3&0.1&0.6\end{array}\right|$

Point a:

The Expected value or the mean value of X with set of possible values D, denoted by E(X) or μ is

$E(X) = $\sum_{x\in D} x\cdot p(x)$

Therefore

$E(X)=16\cdot 0.3+18\cdot 0.1+20\cdot 0.6=18.6$

If the random variable X has a set of possible values D and a probability mass function, then the expected value of any function h(X), denoted by E[h(X)] is computed by

$E[h(X)] = $\sum_{D} h(x)\cdot p(x)$

So $h(X) = X^2$ and

$E[h(X)] = $\sum_{D} h(x)\cdot p(x)\\E[X^2]=$\sum_{D}x^2\cdot p(x)\\ E(X^2)=16^2\cdot 0.3+18^2\cdot 0.1+20^2\cdot 0.6\\E(X^2)=349.2$

The variance of X, denoted by V(X), is

$V(X) = $\sum_{D}E[(X-\mu)^2]=E(X^2)-[E(X)]^2$

Therefore

$V(X) = E(X^2)-[E(X)]^2\\V(X)=349.2-(18.6)^2\\V(X)=3.24$

Point b:

We know that the price of a freezer having capacity X is 60X − 650, to find the expected price paid by the next customer to buy a freezer you need to:

From the rules of expected value this proposition is true:

$E(aX+b)=a\cdot E(x)+b$

We have a = 60, b = -650, and E(X) = 18.6. Therefore

The expected price paid by the next customer is

$60\cdot E(X)-650=60\cdot 18.6-650=466$

4 0

2 years ago

Trapezoid $RSTU$ is a cross section of a lampshade. The diagonals of $RSTU$ are congruent, and the measure of $\angle S$ is $112

Alexxandr [17]

Answer:

112°

Step-by-step explanation:

Given that the diagonals of trapezoid RSTU are congruent, it is an Isosceles Trapezoid.

One of the properties of an Isosceles Trapezoid is that the base angles are equal.

Therefore if the measure of angle S=112°, the measure of Angle U will also be 112°.

3 0

2 years ago