What is the probability of randomly guessing at least 8 out of 10 questions correct on a true-or-false quiz?

1 answer:

3 0

P( at least 8 correct ) =
........P( 8 ) + P( 9 ) + P( 10 ) = 
........(10 C 8).5^10 + (10 C 9).5^10 + (10 C 10).5^10 = ........56*.5^10 = 0.0546875 

Note: Let C denote correct and I denote incorrect. Suppose that guessing results in 8 correct and 2 incorrect answers. One possible outcome is CCCCCCCCII, for example. We can think of the number of ways of getting exactly 8 correct to be the same as the number of ways of selecting 8 spots for the correct answers times the number of ways of selecting two spots for the remaining two answers. There are (10 C 8) ways to select the positions for the correct answers and precisely one way to select the remaining two positions for the incorrect answers. Therefore, there are there are 10 C 8 = 45 ways to get 8 correct. Similarly, there are 10 C 9 = 10 ways to get 9 correct, and 10 C 10 = 1 way to get all 10 correct.

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Here is another math question 6/3+(-1/3)

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6/3+(-1/3)
= 6/3-1/3
= 5/3
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Find the slope and y-intercept of the graph of the equation. y= 2x + 7

faust18 [17]

Slope 2
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2 years ago

Recipe ingredients remain in a constant ratio no matter how many servings are prepared. Which table shows a possible ratio table

Phantasy [73]

A table which shows a possible ratio table for ingredients X and Y for the given number of servings is table 4.

<h3>What is a proportion?</h3>

A proportion can be defined as an equation which is typically used to represent (indicate) the equality of two (2) ratios. This ultimately implies that, proportions can be used to establish that two (2) ratios are equivalent and solve for all unknown quantities.

Mathematically, a direct proportion can be represented the following equation:

y = kx

Where:

y and x are the variables.
k represents the constant of proportionality.

Since the recipe ingredients remain in a constant ratio, we have:

k = y/x

For table 1, we have:

k = 2/1 = 2.

k = 3/2 = 1.5.

k = 4/3.

For table 2, we have:

k = 2/1 = 2.

k = 4/2 = 2.

k = 8/3.

For table 3, we have:

k = 2/1 = 2.

k = 3/2 = 1.5.

k = 5/3.

For table 4, we have:

k = 2/1 = 2.

k = 4/2 = 2.

k = 6/3 = 2.

In conclusion, a table which shows a possible ratio table for ingredients X and Y for the given number of servings is table 4 as shown in the image attached below.

Read more on proportionality here: brainly.com/question/12866878

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