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3 years ago

What is -4 3/10 - 8 3/10

Mathematics

2 answers:

nadya68 [22]3 years ago

4 0

Answer:

-12 3/5

Step-by-step explanation:

-4 3/10 - 8 3/10

The signs are the same so we add and then take the sign

4 3/10 + 8 3/10

Add the whole numbers

4+8 = 12

Add the fractions

3/10 + 3/10 = 6/10

Simplify the fraction

6/10 = 3/5

Put them together

12 3/5

Add the sign

-12 3/5

Anna35 [415]3 years ago

3 0

Answer:

Step-by-step explanation:

Change the mixed fraction to improper fraction

-4 3/10 = -43/10

-8 3/10 = -83/10

$-4\frac{3}{10}-8\frac{3}{10}=\frac{-43}{10}-\frac{83}{10}\\\\=\frac{-43-83}{10}\\\\=\frac{-126}{10}\\\\=-12\frac{6}{10}$

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Which explains how the table can be used to predict the cost of any number of students attending the game?

Vesna [10]

Answer:

The answer is B

Step-by-step explanation:

The table is a partial representation of a larger data set. It can be used to generate an equation that is a complete representation of the data set.

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3 years ago

Which of the following is not the equation of the graphed line?

ehidna [41]

Answer:

well, we do not have the options here, but we can find the equation of the graph, so the equations that are different from that are the answer to this question:

in the graph, we can see that it goes through the points:

(0,1) and (2,0)

Remember that the slope of a line that goes through the points (x1, y1) and (x2, y2) is:

s = (y2 - y1)/(x2- x1)

then the slope for our line is:

s = (0 - 1)/(2 -0) = -1/2

Then our line is:

y = -(1/2)*x + b.

b is the y-intercept, and we know that when x = 0 y = 1, then:

1 = -(1/2)*0 + b

1 = b

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5 0

3 years ago

In a study to compare two different corrosion inhibitors, specimens of stainless steel were immersed for four hours in a solutio

djverab [1.8K]

Answer:

$(242-220) -1.988 \sqrt{\frac{20^2}{47} +\frac{31^2}{42}}= 10.862$

$(242-220) +1.988 \sqrt{\frac{20^2}{47} +\frac{31^2}{42}}= 33.138$

And the 95% confidence interval for the difference in the means is given by: $10.862 \leq \mu_A -\mu_B \leq 33.138$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X_A = 242$ sample mean for inhibitor A

$s_A = 20$ sample standard deviation for inhibitor A

$n_A = 47$ sample size for A

$\bar X_B = 220$ sample mean for inhibitor B

$s_B = 31$ sample standard deviation for inhibitor B

$n_B = 42$ sample size for A

Solution to the problem

For this case the confidence interval for the difference of means is given by:

$(\bar X_A -\bar X_B) \pm t_{\alpha/2} \sqrt{\frac{s^2_A}{n_A} +\frac{s^2_B}{n_B}}$

The degrees of freedom are given by:

$df = n_A +n_B -2 = 47+42-2= 87$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,87)".And we see that $t_{\alpha/2}=1.988$