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3 years ago

The half-life of chromium−51 is 27.8 days. How much of a 7.6−oz sample of chromium−51 will remain after 139 days?

1 answer:

6 0

Ending Amount = Beginning Amount / 2^n
where "n" is the number of half-lives
n = 139 / 27.8 = 5 half-lives
Ending Amount = 7.6 oz / 2^5
Ending Amount = 7.6 oz / 32
Ending Amount = .2375 ounces

Source:
http://www.1728.org/halflife.htm

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Answer:

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Step-by-step explanation:

From the question we are told that

The population mean is $\mu = 500$

The standard deviation is $\sigma = 100$

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$P(350 < X 650 ) = P(\frac{ 350 - 500}{ 100}$

Generally

$\frac{X - \mu }{\sigma } = Z (The \ standardized \ value \ of \ X )$

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$P(350 < X 650 ) = P(-1.5$

$P(350 < X 650 ) = P(Z < 1.5) - P(Z < -1.5)$

From the z-table $P(Z < -1.5 ) = 0.066807$

and $P(Z < 1.5 ) = 0.93319$

=> $P(350 < X 650 ) = 0.93319 - 0.066807$

=> $P(350 < X 650 ) = 0.866$

Therefore the percentage is $P(350 < X 650 ) = 86.6\%$

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3 years ago

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Answer: a.This is the average number of days the house stayed on the market before being sold for $150,000.

Step-by-step explanation:

Given: f(p) be the average number of days a house stays on the market before being sold for price p in $1,000s.

To find the meaning f(150),

here p= 150 which means f(150) is the average number of days a house stays on the market before being sold for price 150 in $1,000s.

And 150 in $ 1,000= $150,000

Therefore, f(150) is the average number of days a house stays on the market before being sold for price $150,000.

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3 years ago

Read 2 more answers

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Answer:

Step-by-step explanation:

The rest of the question is: There are 75 pills in the batch.

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$\frac{75}{600}*100 = 12.5 \%$

≈ 13% to the nearest whole number

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3 years ago

Find the standard form of the equation of the parabola with the given characteristics

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Answer:

Step-by-step explanation:

The standard equation of a parabola is

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4 years ago

This is 10 points plz help ( NO LINKS )

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Answer:

side A is 18.75 cm² greater than side B

Step-by-step explanation:

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