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3 years ago

Two equations are given below:

Mathematics

1 answer:

ycow [4]3 years ago

8 0

Hello,

a-3b=4 (1)
a-b=-2 (2)

(1)-(2)==> -2b=6
=>b=-3 and a=-2+(-3)=-5

Answer D

Proof
-5+3=-2
-5-3(-3)=4

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3 Which expression is equivalent to 19 - 27?

Elanso [62]

Answer: 19 + (-27)

Step-by-step explanation:

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2 years ago

Read 2 more answers

PLEASE HELP ME I BEG I WILL GIVE BRAINLIEST

ohaa [14]

Answer:

Mean = (2.2 + 2.4 + 2.5 + 2.5 + 2.6 + 2.7)/6 = 2.48

Standard deviation = √(summation(x - mean)²/n

n = 6

Summation(x - mean)² = (2.2 - 2.48)^2 + (2.4 - 2.48)^2 + (2.5 - 2.48)^2 + (2.5 - 2.48)^2 + (2.6 - 2.48)^2 + (2.7 - 2.48)^2 = 0.1484

Standard deviation = √(0.1484/6

s = 0.16

Standard error = s/√n = 0.16/√6 = 0.065

Part B

Confidence interval is written as sample mean ± margin of error

Margin of error = z × s/√n

Since sample size is small and population standard deviation is unknown, z for 98% confidence level would be the t score from the student t distribution table. Degree of freedom = n - 1 = 6 - 1 = 5

Therefore, z = 3.365

Margin of error = 3.365 × 0.16/√6 = 0.22

Confidence interval is 2.48 ± 0.22

Part C

We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

H0: µ = 2.3

For the alternative hypothesis,

H1: µ > 2.3

This is a right tailed test

Since the number of samples is small and no population standard deviation is given, the distribution is a student's t.

Since n = 6

Degrees of freedom, df = n - 1 = 6 - 1 = 5

t = (x - µ)/(s/√n)

Where

x = sample mean = 2.48

µ = population mean = 2.3

s = samples standard deviation = 0.16

t = (2.48 - 2.3)/(0.16/√6) = 2.76

We would determine the p value using the t test calculator. It becomes

p = 0.02

Assuming significance level, alpha = 0.05.

Since alpha, 0.05 > than the p value, 0.02, then we would reject the null hypothesis. Therefore, At a 5% level of significance, the sample data showed significant evidence that the mean absolute refractory period for all mice when subjected to the same treatment increased.

Step-by-step explanation:

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2 years ago

Select the correct answer from each drop-down menu.

Ostrovityanka [42]

Answer:

Both questions are true.

Step-by-step explanation:

The general mathematical equation of a line can be written as $y = ax + b$ .

If we rearrange the two equations given in the question as follows:

$5y = 3x + 22$ and $20y = 12x + 11$

We can see that they follow the general equation we defined earlier so we can say that they represents linear lines.

The $20y = 12x + 88$ given in the second question also represents a similar linear line with a different slope.

So the two questions are both true.

I hope this answer helps.

4 0

2 years ago

Please help with these math questions

Alexxx [7]

3) This is definitely a positive association, but the question is - is it linear?
Since a somewhat straight line can be drawn through the points, it is linear.

Answer: positive linear association

4) Find the slope using the formula
$m = \frac{y2 - y1}{x2 - x1}$

m = 43 - 48/ 4 - 2 = -5/2 = -2.5
Negative association, but is it linear? Lets find out

Oh no! It seems that their is not a pattern in the association, so its nonlinear!

Answer: Negative nonlinear association

5) $m = \frac{y2 - y1}{x2 - x1}$
m = 80 - 66/ 5 - 3
m = 14/2
m = 7

Positive! But is it linear??
Let us draw a graph this time.

I know my graph is messy, but can you see the nonlinear-ness? It doesnt form a straight line!

Answer: Positive nonlinear association

Hope this helped. :)

8 0

3 years ago

What were various reasons why Americans settlers migrated westward during the late 1800’s

inysia [295]

to fulfill manifest destiny, the American dream to expand, as well as reach the ocean on the west in order to have more options for trade

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3 years ago