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On a multiple-choice test. Abby randomly guesses on all seven questions. Each question

Murrr4er [49]

Answer:

0.173 probability that she gets exactly three questions correct.

Step-by-step explanation:

For each question, there are only two possible outcomes. Either she guesses the correct answer, or she does not. The probability of guessing the correct answer for a question is independent of other questions. So we use the binomial probability distribution 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.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

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

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

Seven questions:

This means that $n = 7$

Each question has four choices.

Abby guesses, which means that $p = \frac{1}[4} = 0.25$

Find the probability to the nearest thousandth, that Abby gets exactly three questions correct.

This is P(X = 3).

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 3) = C_{7,3}.(0.25)^{3}.(0.75)^{4} = 0.173$

8 0

3 years ago

What is the greatest common factor of 10, 20, and 50?

Viefleur [7K]

Answer:

10

Step-by-step explanation:

first you need to find the prime factors of the three numbers

ex:

prime factor of 18= $2*3*3$

prime of 24= $2*2*2*3$

there is one 2 and one 3 in common

greatest common multiple 2*3=6

so the greatest common multiple is ten because it is the only one that can divide between all three evenly.

$10=10/10=1\\20=20/10=2\\50=50/10=5$

so 10 is your answer

6 0

3 years ago

-4w+18w+2=10-6w <br><br> What is w?

kiruha [24]

Answer:

w = .5

Step-by-step explanation:

-4w + 18w+2=10 -6w

14w + 2 -2 = 10 -2 -6w

14w + 2w = 8 - 2w + 2w

16w = 8

16w/16 = 8/16

w = .5

8 0

3 years ago

Read 2 more answers

Could someone answer these 3 for me?

KengaRu [80]

Answer:

x=4.77

Angle 3=98.32 degrees

Angle 6= 81.68 degrees

Step-by-step explanation:

(Assuming these are parallel lines), Angle 3 and angle 5 are equal because they are alternate Angles. Therefore we can write the following equation to solves for x:

16x+22=3x+84 (angle 3=angle5)

Which we can now solve:

16x +22 - 22 - 3x=3x-3x+84-22

13x=62

13x/13=62/13

x=4.77 (2dp)

We can then use this x to calculate angle 3:

16(4.77)+22

76.33+22=98.32 degrees

Finally,

Angle 6 and angle 3 are interior angles, so they add up to 180 degrees.

So to find angle 6,we can just subtract angle 3 from 180:

180-98.32=81.68 degrees.

Hope this helped!

6 0

3 years ago

Is the answer a b c or d???

Hoochie [10]

A) $7. 69 change she will get back when she use 50.00 for her pants and sweater

7 0

3 years ago