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3 years ago

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Please help fast I am really struggling plus I am being timed please help hurry !!thank you in Advance! Plus if you want a 10 po

ints✨✨✨

1 answer:

Oksanka [162]3 years ago

7 0

Answer:

Um

Step-by-step explanation:

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There is a beaker of 3.5% acid solution and a beaker of 6% acid solution in the science lab. Mr. Larson needs 200 milliliters of

oksian1 [2.3K]

Et x = the volume of the 3.5% solution
<span>Let y = the volume 6% solution </span>

<span>(3.5%)x + (6%)y = (4.5%)(200) </span>
<span>0.035)x + 0.06y = 0.045(200) </span>
<span>0.035x + 0.06y = 9 ( Equation 1 )</span>

<span>x + y = 200 ( Equation 2 )</span>
<span>x = 200 - y </span>

<span>Substitute x = 200 - y into equation 1: </span>
<span>0.035x + 0.06y = 9 </span>
<span>0.035(200 - y) + 0.06y = 9 </span>
<span>7 - 0.035y + 0.06y = 9 </span>
<span>0.06y - 0.035y = 9 - 7 </span>
<span>0.025y = 2 </span>
<span>y = 2/(0.025) </span>
<span>y = 80 mL (the volume of 6% solution.)</span>

<span>Substitute y = 80 into equation 2: </span>
<span>x + y = 200 </span>
<span>x + 80 = 200 </span>
<span>x = 200 - 80 </span>
<span>x = 120 mL (the volume of the 3.5% solution.)</span>

<span>Therefore, Mr. Larson should combine 120 mL of the 3.5% solution </span>
<span>and 80 mL of the 6% solution to make 200 mL of 4.5% solution. </span>

<span>Answer is 120 mL of the 3.5% solution & 80 mL of the 6% solution

Hope I helped :)</span>

5 0

4 years ago

3/4 : 1/2 how do I make these fractions in this ration into decimals

Svet_ta [14]

0.75 : 0.5

3 • 25 = 75,, 4 • 25 = 100,, making it 0.75

1 • 50 = 50,, 2 • 50 = 100,, making it 0.5

4 0

4 years ago

The quotient of 2 and a number x,times 3

Sati [7]

Answer:

(2/x)3 or 3(2/x

Step-by-step explanation:

The quotient of 2 and x is expressed as 2/x Multiplied by 3 can be expressed as (2/x)3 or 3(2/x)

6 0

3 years ago

Help needed now with Math question.

saveliy_v [14]

Answer:

is the last one

Step-by-step explanation:

5 0

3 years ago

A population of plastic chairs in a factory has a weight's mean of 1.5 kg and a standard deviation of 0.1 kg . Suppose a sample

Firlakuza [10]

Answer:

0.9544 = 95.44% probability that the sample mean will be within +0.02 of the population mean.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use 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.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question, we have that:

$\mu = 1.5, \sigma = 0.1, n = 100, s = \frac{0.1}{\sqrt{100}} = 0.01$

What is the probability that the sample mean will be within +0.02 of the population mean?

Sample mean between 1.5 - 0.02 = 1.48 kg and 1.5 + 0.02 = 1.52 kg, which is the pvalue of Z when X = 1.52 subtracted by the pvalue of Z when X = 1.48. So

X = 1.52

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

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{1.52 - 1.5}{0.01}$

$Z = 2$

$Z = 2$ has a pvalue of 0.9772

X = 1.48 

$Z = \frac{X - \mu}{s}$

$Z = \frac{1.48 - 1.5}{0.01}$

$Z = -2$

$Z = -2$ has a pvalue of 0.0228

0.9772 - 0.0228 = 0.9544

0.9544 = 95.44% probability that the sample mean will be within +0.02 of the population mean.

3 0

3 years ago