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2 years ago

Can you please help Imao the first answer gets the brainiest

Mathematics

1 answer:

Eduardwww [97]2 years ago

7 0

Answer: 4 for the first one and 4.25

Explanation:

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The time needed to complete a final examination in a particular college course is normallydistributed with a mean of 80 minutes

Artist 52 [7]

Answer:

a) 0.023

b) 0.286

c) 10 students will be unable to complete the exam inthe allotted time.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 80 minutes

Standard Deviation, σ = 10 minutes

We are given that the distribution of time to complete an exam is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P(completing the exam in one hour or less)

P(x < 60)

$P( x < 60) = P( z < \displaystyle\frac{60 - 80}{10}) = P(z < -2)$

Calculation the value from standard normal z table, we have,

$P(x < 60) =0.023= 2.3\%$

b) P(complete the exam in more than 60 minutes but less than 75 minutes)

$P(60 \leq x \leq 75) = P(\displaystyle\frac{60 - 80}{10} \leq z \leq \displaystyle\frac{75-80}{10}) = P(-2 \leq z \leq -0.5)\\\\= P(z \leq -0.5) - P(z < -2)\\= 0.309- 0.023 = 0.286= 28.6\%$

c) P(completing the exam in more than 90 minutes)

P(x > 90)

$P( x > 90) = P( z > \displaystyle\frac{90 -80}{10}) = P(z > 1)$

$= 1 - P(z \leq 1)$

Calculation the value from standard normal z table, we have,

$P(x > 90) = 1 - 0.8413 = 0.1587 = 15.87\%$

15.87% of children of class will require more than 90 minutes to complete the test.

Number of children =

$\dfrac{15.87}{100}\times 60 = 9.52\approx 10$

Approximately, 10 students of class will require more than 90 minutes to complete the test.

4 0

3 years ago

The distance between major cracks in a highway follows an exponential distribution with a mean of 5 miles. (a) What is the proba

Nonamiya [84]

Answer:

$P(Y=0) = 0.1353$

Step-by-step explanation:

From the question we are told that:

Exponential distribution mean $\=x = 5 miles$

Distance $d=10miles$

Generally the equation for Exponential distribution is mathematically given by

$\lambda=\frac{1}{E(X)}$

$\lambda=\frac{1}{5}$

Therefore

Possion Y

$10\lambda=10*(1/5)$

$10\lambda=2$

Generally the equation for The probability that there are no major cracks in a 10 mile stretch of the highway is mathematically given by

$P(Y=0) = \frac{e-2 (2)0}{0!}$

$P(Y=0) = e-2$

$P(Y=0) = 0.1353$

7 0

3 years ago

0.750 + 0.375 + 0.625

KATRIN_1 [288]

Answer:

1.75

Step-by-step explanation:

5 0

3 years ago

The landscaping project you are working on has a circular flower garden 18 feet in diameter. To determine the number of plants t

Naddik [55]

Answer:

The approximate area of the flower garden is $254.34\ ft^{2}$

Step-by-step explanation:

we know that

The area of the circle ( circular flower garden) is equal to

$A=\pi r^{2}$

we have

$r=18/2=9\ ft$ ----> the radius is half the diameter

substitute

$A=\pi (9^{2})=81\pi\ ft^{2}$ ----> exact value of the area

Find the approximate value of the area

$81(3.14)=254.34\ ft^{2}$

4 0

3 years ago

Problem 1 Find the mBC.

son4ous [18]

Answer:

m BC = 100

Step-by-step explanation:

Since the angle is at the center, the arc has the same measurement as the angle

m BC = 100

4 0

3 years ago