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marta [7]
3 years ago
8

What quantity of a 30% solution do you need to make 150 mL of a 20% solution?

Mathematics
1 answer:
Bumek [7]3 years ago
7 0

Answer:

Volume required = 100mL

Step-by-step explanation:

Let the volume of 30% solution required be = V mL

Amount of solute in V mL of solution = 30% of V = 0.3V...............(i)

This amount is also present in 150 mL of 20% solution

For 150 mL of 20% solution we have amount of solute = 150 mL X 20%

                                                                                          = 30..............(ii)

Thus equating i and ii we get

0.3V = 30

Thus V =100 mL

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Consider the probability that greater than 94 out of 153 people will not get the flu this winter. Assume the probability that a
Hatshy [7]

Answer:

0.8212 = 82.12% probability that greater than 94 out of 153 people will not get the flu this winter.

Step-by-step explanation:

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

E(X) = np

The standard deviation of the binomial distribution is:

\sqrt{V(X)} = \sqrt{np(1-p)}

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that \mu = E(X), \sigma = \sqrt{V(X)}.

In this problem, we have that:

p = 0.65, n = 153. So

\mu = E(X) = 153*0.65 = 99.45

\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{153*0.65*0.35} = 5.9

Consider the probability that greater than 94 out of 153 people will not get the flu this winter

This probability is 1 subtracted by the pvalue of Z when X = 94. So

Z = \frac{X - \mu}{\sigma}

Z = \frac{94 - 99.45}{5.9}

Z = -0.92

Z = -0.92 has a pvalue of 0.1788

1 - 0.1788 = 0.8212

0.8212 = 82.12% probability that greater than 94 out of 153 people will not get the flu this winter.

7 0
3 years ago
What is the solution to y=3/7x -1?
DedPeter [7]
Every point on the line 3/7x -1 is a solution

Unless there is another line provided...
6 0
3 years ago
Carly eats a bowl of granola for breakfast every morning. She wonders how much granola she eats in a year. If Carly eats about o
sp2606 [1]
36 pounds of granola
7 0
3 years ago
Read 2 more answers
What is the answer for the three questions please help
ycow [4]
The driver can drive around the track 54 times for $12. Thus for one dollar, he can drive around the track 54/12 times, or 4.5 times. If for each dollar he drives around 4.5 times, for 8 dollars, he can drive around 8*4.5 or 36 times.

If there are 207 students in 9 classes, in 1 class, there are 207/9 students, or 23 students per class. Since there are 23 students per class and there are  classes, there are a total of 23*6 or 138 students in total.

Liam practices 24 times in 4 days. Thus he practices 24/4 or 6 times per day. His brother practices 12 times in 3 days. Thus he practices 12/3 or 4 times a day. Thus their rates are not equivalent.
7 0
3 years ago
Jabri is thinking of three numbers. The greatest number is twice as large as the least number. The midde number is three more th
quester [9]

Answer:

Step-by-step explanation:

Givens

Let the least number = x

Let the largest number = 2x

Let the second number = x + 3

The sum = 75

Equation

x + 2x + x + 3 = 75                    Combine the terms on the left

Solution

4x + 3 = 75                               Subtract 3 from both sides

4x +3-3= 75-3

4x = 72                                      Divide by 4

4x/4 = 72/4

x = 18

Answer

Smallest number = 18

Second number = 18 + 3 = 21

Largest number = 2*18 = 36

Sum  =                               75

6 0
3 years ago
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