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3 years ago

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A bag contains 6 red balls and blue balls. 4 balls are selected at random. find the probability of selecting 4 red balls.

1 answer:

masya89 [10]3 years ago

8 0

Another way is to note that there are <span><span>(<span>104</span>)</span><span>(<span>104</span>)</span></span> (“10 choose 4”) ways to select 4 balls from a collection of 10. If 4 of those 10 balls are “special” in some way (in this case, “special” = “red”), then the number of ways to choose 4 special balls is <span><span>(<span>44</span>)</span><span>(<span>44</span>)</span></span>. (The factor of <span><span>(<span>60</span>)</span><span>(<span>60</span>)</span></span> is included to convey that, after choosing 4 special balls, we choose none of the 6 non-special balls.) This line of reasoning gives the second expression.

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A stack of bricks is 3 1/2 feet high. If each brick is 1 3/4 inches high, how many bricks are in the stack?

Arisa [49]

We have to divide 3 1/2 by 1 3/4:
3 1/2 : 1 3/4 = 7/2 : 7/4 = 7/2 * 4/7 = 2
Answer:
A ) 2 bricks are in the stack.

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3 years ago

Assume that trees are subjected to different levels of carbon dioxide atmosphere with 7% of the trees in a minimal growth condit

taurus [48]

Answer: The mean and standard deviation are 567.2 and 89.88 resp.

Step-by-step explanation:

Since we have given that

For 370 parts per million = 7% = 0.07

For 440 parts per million = 10% = 0.10

For 550 parts per million = 49% = 0.49

For 670 parts per million = 34% = 0.34

So, Mean of the carbon dioxide atmosphere for these trees would be

$E[x]=370\times 0.07+440\times 0.1+550\times 0.49+670\times 0.34=567.2$

And

$E[x^2]=370^2\times 0.07+440^2\times 0.1+550^2\times 0.49+670^2\times 0.34=329794$

So, Variance would be

$Var\ x=E[x^2]-E[x]^2=329794-567.2^2=8078.16$

So, the standard deviation would be

$\sigma=\sqrt{8078.16}=89.88$

Hence, the mean and standard deviation are 567.2 and 89.88 resp.

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4 years ago

Melissa mows many lawns in her neighborhood. She mows lawns for $95 per lawn. She also offers full landscape maintenence for $12

olga55 [171]

9.52

125 * 4 = 500

500 * 9.52 = 4,760

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3 years ago

Which would the phrase "two times the quotient of a number and 3" look like as a variable expression?

Naya [18.7K]

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3 years ago

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Veseljchak [2.6K]

Answer:

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Step-by-step explanation:

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3 years ago