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bearhunter [10]

3 years ago

8

Suppose, you are attending an exam where there are 9 multiple choice questions with 3 options in each. A question can have multi

ple correct answers, and in that case, you have to check all of the correct answers to get the question right. a. What is the probability that you'll get exactly 6 of the questions right? b. What is the probability that you'll get at most 6 of the questions right?

1 answer:

Anastaziya [24]3 years ago

8 0

Answer:

a. The probability of getting exactly 6 of the question right is approximately 0.164

b. The probability of getting at most 6 of the questions right is approximately 0.93

Step-by-step explanation:

The given parameters are;

The number of multiple choice questions = 9 multiple choice questions

The number of options in each question = 3 options

The number of outcomes to the answers of the question = 2, Right or Wrong

Therefore, the probability of having a question right, p = 1/2

The probability of having a question wrong, q = 1 - p = 1 - 1/2 = 1/2

By binomial probability theorem, we have;

The probability of getting exactly 6 of the question right, P(6), is given as follows;

P(6) = ₉C₆·p⁶·(q)⁹⁻⁶ = 84 × (1/2)⁶ × (1/2)³ = 0.1640625

The probability of getting exactly 6 of the question right, P(6) = 0.1640625 ≈ 0.164

b. The probability of P(at most 6 of the questions right) = P(X ≤ 6)

P(at most 6 of the questions right) = P(X ≤ 6) = 1 - P(X ≥ 7)

∴ P(X ≤ 6) = 1 - (₉C₇·p⁷·q⁹⁻⁷) = 1 -(36·(1/2)⁷·(1/2)² = 0.9299875

The probability of P(at most 6 of the questions right) = P(X ≤ 6) = 0.9299875 ≈ 0.93.

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They have the same rate of change.

Step-by-step explanation:

They both increase two degrees every hour.

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4 years ago

The base of a triangle exceeds the height by 7 centimeters. If the area is 400 square centimeters, find the length of the base a

zvonat [6]

Answer:

Base = 32 cm

Height = 25 cm

Step-by-step explanation:

Area of a triangle can be calculated as:

$Area = \frac{1}{2}\times Base \times Height$

We are given that the base of triangle exceeds the height by 7 cm. This can be expressed in an equation form as:

Base = Height + 7

Lets use B to represent base and H to represent height

B = H + 7

The equation of area can be stated as:

$Area=\frac{1}{2}bh\\\\ Area=\frac{1}{2}(h+7)(h)\\\\ 400=\frac{1}{2}h(h+7)\\\\ 800=h^{2}+7h\\\\ h^{2}+7h-800=0$

This is a quadratic equation which can be solved using a quadratic equation as shown below:

$h=\frac{-7+-\sqrt{49-4(1)(-800)} }{2(1)} \\\\ h=\frac{-7+-57}{2}\\\\h=-32,25$

Since the height cannot be negative, we'll consider the positive value only i.e height is equal to 25 cm.

Therefore, the length of base will be 25 + 7 = 32 cm.

8 0

4 years ago

What is the lcd of (3x)/(x + 3), 3/(x ^ 2 - 9)

Rudik [331]

Answer:

Simplify the denominator.

Tap for more steps...

x

(

x

+

3

)

(

x

−

3

)

⋅

3

x

x

2

−

5

x

+

6

Factor

x

2

−

5

x

+

6

using the AC method.

Tap for more steps...

x

(

x

+

3

)

(

x

−

3

)

⋅

3

x

(

x

−

3

)

(

x

−

2

)

Finding the LCD of a list of values is the same as finding the LCM of the denominators of those values.

(

x

+

3

)

(

x

−

3

)

,

(

x

−

3

)

(

x

−

2

)

The LCM is the smallest positive number that all of the numbers divide into evenly.

1. List the prime factors of each number.

2. Multiply each factor the greatest number of times it occurs in either number.

The number

1

is not a prime number because it only has one positive factor, which is itself.

Not prime

The LCM of

1

,

1

is the result of multiplying all prime factors the greatest number of times they occur in either number.

1

The factor for

x

+

3

is

x

+

3

itself.

(

x

+

3

)

=

x

+

3

(

x

+

3

)

occurs

1

time.

The factor for

x

−

3

is

x

−

3

itself.

(

x

−

3

)

=

x

−

3

(

x

−

3

)

occurs

1

time.

The factor for

x

−

2

is

x

−

2

itself.

(

x

−

2

)

=

x

−

2

(

x

−

2

)

occurs

1

time.

The LCM of

x

+

3

,

x

−

3

,

x

−

3

,

x

−

2

is the result of multiplying all factors the greatest number of times they occur in either term.

(

x

+

3

)

(

x

−

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(

x

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2

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Step-by-step explanation:

there does that help

6 0

4 years ago

Which two tables represent the same function?

topjm [15]

Answer:

The 1st and the 5th tables represent the same function

Step-by-step explanation:

* Lets explain how to solve the problem

- There are five tables of functions, two of them are equal

- To find the two equal function lets find their equations

- The form of the equation of a line whose endpoints are (x1 , y1) and

(x2 , y2) is $\frac{y-y_{1}}{x-x_{1}}=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

* Lets make the equation of each table

# (x1 , y1) = (4 , 8) and (x2 , y2) = (6 , 7)

∵ x1 = 4 , x2 = 6 and y1 = 8 , y2 = 7

∴ $\frac{y-8}{x-4}=\frac{7-8}{6-4}$

∴ $\frac{y-8}{x-4}=\frac{-1}{2}$

- By using cross multiplication

∴ 2(y - 8) = -1(x - 4) ⇒ simplify

∴ 2y - 16 = -x + 4 ⇒ add x and 16 for two sides

∴ x + 2y = 20 ⇒ (1)

# (x1 , y1) = (4 , 5) and (x2 , y2) = (6 , 4)

∵ x1 = 4 , x2 = 6 and y1 = 5 , y2 = 4

∴ $\frac{y-5}{x-4}=\frac{4-5}{6-4}$

∴ $\frac{y-5}{x-4}=\frac{-1}{2}$

- By using cross multiplication

∴ 2(y - 5) = -1(x - 4) ⇒ simplify

∴ 2y - 10 = -x + 4 ⇒ add x and 10 for two sides

∴ x + 2y = 14 ⇒ (2)

# (x1 , y1) = (2 , 8) and (x2 , y2) = (8 , 5)

∵ x1 = 2 , x2 = 8 and y1 = 8 , y2 = 5

∴ $\frac{y-8}{x-2}=\frac{5-8}{8-2}$

∴ $\frac{y-8}{x-2}=\frac{-3}{6}=====\frac{y-8}{x-2}=\frac{-1}{2}$

- By using cross multiplication

∴ 2(y - 8) = -1(x - 2) ⇒ simplify

∴ 2y - 16 = -x + 2 ⇒ add x and 16 for two sides

∴ x + 2y = 18 ⇒ (3)

# (x1 , y1) = (2 , 10) and (x2 , y2) = (6 , 14)

∵ x1 = 2 , x2 = 6 and y1 = 10 , y2 = 14

∴ $\frac{y-10}{x-2}=\frac{14-10}{6-2}$

∴ $\frac{y-10}{x-2}=\frac{4}{4}======\frac{y-10}{x-2}=1$

- By using cross multiplication

∴ (y - 10) = (x - 2)

∴ y - 10 = x - 2 ⇒ add 2 and subtract y in the two sides

∴ -8 = x - y ⇒ switch the two sides

∴ x - y = -8 ⇒ (4)

# (x1 , y1) = (2 , 9) and (x2 , y2) = (8 , 6)

∵ x1 = 2 , x2 = 8 and y1 = 9 , y2 = 6

∴ $\frac{y-9}{x-2}=\frac{6-9}{8-2}$

∴ $\frac{y-9}{x-2}=\frac{-3}{6}======\frac{y-9}{x-2}=\frac{-1}{2}$

- By using cross multiplication

∴ 2(y - 9) = -1(x - 2) ⇒ simplify

∴ 2y - 18 = -x + 2 ⇒ add x and 18 for two sides

∴ x + 2y = 20 ⇒ (5)

- Equations (1) and (5) are the same

∴ The 1st and the 5th tables represent the same function

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