please help quick pleaseeee

Answer:

a. 0.008 = 0.8% probability that the person will answer all three questions correctly.

b. 0.096 = 9.6% probability that the person will answer exactly two questions correctly.

c. 0.384 = 38.4% probability that the person will answer exactly one question correctly.

d. 0.512 = 51.2% probability that the person will answer no questions correctly.

e. The expected value of the person’s score for the three questions is -0.2.

Step-by-step explanation:

For each question, there are only two possible outcomes. Either the person answers it correctly, or they do not. The probability of a person answering a question correctly is independent of any other question. This means that the binomial probability distribution is used 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.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

Each question has five possible answers.

Person has no idea which option is correct, so the probability of answering correctly is:

[tex]p = \frac{1}{5} = 0.2[/tex]

Three questions:

This means that [tex]n = 3[/tex]

a. What is the probability that the person will answer all three questions correctly?

This is [tex]P(X = 3)[/tex]. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 3) = C_{3,3}.(0.2)^{3}.(0.8)^{0} = 0.008[/tex]

0.008 = 0.8% probability that the person will answer all three questions correctly.

b. What is the probability that the person will answer exactly two questions correctly?

This is [tex]P(X = 2)[/tex]. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 2) = C_{3,2}.(0.2)^{2}.(0.8)^{1} = 0.096[/tex]

0.096 = 9.6% probability that the person will answer exactly two questions correctly.

c. What is the probability that the person will answer exactly one question correctly?

This is [tex]P(X = 1)[/tex]. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 1) = C_{3,1}.(0.2)^{1}.(0.8)^{2} = 0.384[/tex]

0.384 = 38.4% probability that the person will answer exactly one question correctly.

d. What is the probability that the person will answer no questions correctly?

This is [tex]P(X = 0)[/tex]. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{3,0}.(0.2)^{0}.(0.8)^{3} = 0.512[/tex]

0.512 = 51.2% probability that the person will answer no questions correctly.

e. Suppose that the person gets one point of credit for each correct answer and that 1/3 point is deducted for each incorrect answer. What is the expected value of the person’s score for the three questions?

The expected number of correct answer is:

[tex]E(X) = np = 3*0.2 = 0.6[/tex]

And the expected number of wrong answers is 3 - 0.6 = 2.4. So, the expected score is:

[tex]S(x) = 0.6 - \frac{2.4}{3} = 0.6 - 0.8 = -0.2[/tex]

The expected value of the person’s score for the three questions is -0.2.

Answer:

$5900

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Algebra I

Simple Interest Rate Formula: A = P(1 + rt)

Step-by-step explanation:

Step 1: Define

Identify variables

P = 5000

r = 3% = 0.03

t = 6

Step 2: Find Interest

9514 1404 393

Answer:

  x = 142

Step-by-step explanation:

You want to find x such that ...

  [tex]\sqrt{x+2} -15=-3\qquad\text{given}\\\\\sqrt{x+2} =12\qquad\text{add 15}\\\\x+2=144\qquad\text{square both sides}\\\\\boxed{x=142}\qquad\text{subtract 2 to get x by itself}[/tex]

Answer:

a

Step-by-step explanation:

Answer:

c. As sample size increases, standard error decreases.

Step-by-step explanation:

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

Thus:

The standard error is inversely proportional to the square root of the sample size, that is, as the sample size increases, the standard error decreases, and the correct answer is given by option c.

Answer:

[tex]P(x < 4) = \frac{9}{50}[/tex]

Step-by-step explanation:

Given

[tex]n(S) = 50[/tex]

See attachment for distribution

Required

[tex]P(x < 4)[/tex]

This is calculated as:

[tex]P(x < 4) = \frac{n(1) + n(2) + n(3)}{n(S)}[/tex]

Using the data on the frequency distribution table, we have:

[tex]P(x < 4) = \frac{4 + 2 + 3}{50}[/tex]

[tex]P(x < 4) = \frac{9}{50}[/tex]

Answer:

Period: [tex]\pi[/tex]

Phase shift: n

Step-by-step explanation:

Tangent function:

Has the following format:

[tex]f(x) = \tan{ax - n}[/tex]

In which the period is [tex]\frac{\pi}{x}[/tex] and the phase shift is n.

In this question:

[tex]f(x) = -4\tan{(x-n)}[/tex]

[tex]a = 1[/tex], and thus, the period is [tex]\pi[/tex], with a phase shift of n.

Answer:

The smaller number is 4√2 and the larger number is (4√2 + 1).

Step-by-step explanation:

Let the two numbers be x and y, where y is the larger of the two numbers.

Since y is the larger number, it is one more than the smaller number. So:

[tex]y=x+1[/tex]

When negative two times the smaller is added to the square of the larger, the result is 33. In other words:

[tex]-2x+y^2=33[/tex]

Substitute:

[tex]-2x+(x+1)^2=33[/tex]

Solve for x. Square:

[tex]-2x+(x^2+2x+1)=33[/tex]

Simplify:

[tex]x^2+1=33[/tex]

Subtract one from both sides:

[tex]x^2=32[/tex]

And take the square root of both sides:

[tex]x=\pm\sqrt{32}=\pm 4\sqrt{2}[/tex]

Since y is positive, we can ignore the negative case. So, the smaller number is:

[tex]x=4\sqrt{2}\approx5.66[/tex]

And the larger number is:

[tex]y = 4\sqrt{2} + 1 \approx6.66[/tex]

9514 1404 393

Answer:

  160 cm³

Step-by-step explanation:

The ratio of the linear dimensions is the square root of the ratio of areas:

  scale factor B/A= √(64/144) = 8/12 = 2/3

The ratio of volumes is the cube of the scale factor:

  (volume B)/(volume A) = (2/3)³ = 8/27

Then the volume of pyramid B is ...

  volume B = (volume A) × (volume B)/(volume A)

  = (540 cm³) × (8/27) = 160 cm³ . . . . volume of pyramid B

_____

Equivalently, the ratio of volumes is the 3/2 power of the ratio of areas.

 Vb = Va(64/144)^(3/2) = (540 cm³)(4/9)^(3/2) = (540)(8/27) cm³ = 160 cm³

He used 620 gallons of gas

Answer: the required sample size =1658944

Step-by-step explanation:

When the prior population proportion for the study is unknown , then the formula for sample size is [tex]Sample \ size = 0.25(\dfrac{z^*}{Margin\ of \ error})^2[/tex]

z-value for 99% confidence = 2.576

[tex]Sample \ size = 0.25(\dfrac{2.576}{0.001})^2\\\\=0.25(2576)^2\\\\=1658944[/tex]

Hence, the required sample size =1658944

9514 1404 393

Answer:

  30 grams

Step-by-step explanation:

The time 120 seconds is 4 times the half-life of 30 seconds. That means (1/2)^4 = 1/16 of the original amount will remain. That is (480 g)(1/16) = 30 g.

  30 g of the radioactive rhodium will be left

Answer:

.101501615

.84982392

.901244701

Step-by-step explanation:

For this question use a binomial distribtuion

a.

12C3*.44³*(1-.44)⁹= .101501615

b.

to find at least 4 find the probability of less than 4 and take its compliment

12C0*(1-.44)¹²+12C1*.44*(1-.44)¹¹+12C2*.44²*(1-.44)¹⁰+12C3*.44³*(1-.44)⁹= .15017608

1-.15017608=.84982392

c.

To find less than eight's probability find the proability of at least 8 and take its compliment

12C8*.44⁸(1-.44)⁴+12C9*.44⁹(1-.44)³+12C10*.44¹⁰(1-.44)²+12C11*.44¹¹*(1-.44)+12C12*.44¹²= .098755299

1-.098755299= .901244701

Answer:

since her score was -12 from being perfect

if she had scored 12 more points her score would have been perfect .

that is difference between her score and the perfect score o each quiz was 12

Answer:

C. [tex]\frac{}{AB}[/tex]

Step-by-step explanation:

You can solve this in two ways, firstly by eliminating all the wrong answers, and secondly by just knowing that the horizontal line in [tex]_[/tex][tex]\frac{}{AB}[/tex] means that we are talking about a line.

This is how we solve this question by using the eliminating process.

(A. ∠C) is not the right answer because the ∠ sign lets us know that this answer represents an angle, not a line

(B. B) is not the right answer because it represent a point, not a line (in math we use a singular capital letter to represent points)

(D. ΔABC) is not the right answer because the Δ sign lets us know that the answer represents a triangle, not a line.

Therefore, the only option left is C. [tex]\frac{}{AB}[/tex]

Answer:

?????????????????????????

Answer:

60m^2 is the answer im pretty sure

Step-by-step explanation:

yeah man thats it

Completing the square gives

[tex]x^2-2x-2=(x-1)^2-3[/tex]

and comparing to [tex]y=x^2[/tex], the graph of [tex]y=x^2-2x-2[/tex] would be a horizontal shift to the right by 1 unit, and a vertical shift down by 3 units.

Hope this help!!!

Have a nice day!!!

Answer:

T = k * (A/W)

Step-by-step explanation:

Answer:

All of the following solid figures except a square pyramid have two bases.

Answer:

?

Step-by-step explanation:

i dont now how to arrange

Answer:

12

Step-by-step explanation:

trust me bro

Answer:

x=-10

Step-by-step explanation:

2(x+3)=x-4

2*x+2*3=x-4

2x+6=x-4

2x-x=-4-6

x=-10

Answer:

[tex]x = - 10[/tex]

Step-by-step explanation:

Let's solve:

[tex]2(x+3)=x−4[/tex]

Step 1: Simplify both sides of the equation.

[tex]2(x+3)=x−4 \\ (2)(x)+(2)(3)=x+−4(Distribute) \\ 2x+6=x+−4 \\ 2x+6=x−4[/tex]

Step 2: Subtract x from both sides.

[tex]2x+6−x=x−4−x \\ x+6=−4[/tex]

Step 3: Subtract 6 from both sides.

[tex]x+6−6=−4−6 \\ x=−10[/tex]

Answer:

the last one is correct.............

Answer:

w ≈ 21.053 inches

l ≈ 28.353 inches

Step-by-step explanation:

Answer:

37.7

Step-by-step explanation:

EF and ED define the Tangent of D

Tan(37) = side opposite D / side adjacent to D

Opposite means a line (FE) that is not connected to the angle. It is never the longest line (hypotenuse) in a Right Triangle

Adjacent means the leg that is connected to the angle, but is not the hypotenuse.

Tan(D) = opposite over adjacent

Opposite = x

Adjacent = 50

Tan(37) = 0.7536 rounded to 4 places, but I've kept the exact value in my calculator.

0.7536 = x / 50     Multiply both sides by 50

0.7536*50 = x

x = 37.6777

The nearest 1/10 is 37.7

Answer:

1 / 1365

Step-by-step explanation:

Given that :

Number of employees to choose from = 15

Number of employees to be chosen = 4

Probability of choosing You, Kyle, Carol and Adam

Recall ;

P(A) = number of required outcome / Total possible outcomes

Number of required outcome = 4C4

Total possible outcomes = 15C4

nCr = n! ÷ (n-r)!r!

Using calculator to save computation time :

15C4 = 1365

4C4 = 1

P(choosing you, Kyle, Carol and Adam) :

1 / 1365