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2 years ago

2.5(a + 4) + 0.5a = 12.4

Mathematics

1 answer:

finlep [7]2 years ago

4 0

Answer:

a=0.8

Step-by-step explanation:

First I distributed 2.5 into (a+4) and got (2.5a+10)+0.5a=12.4. I then combined like terms which are 2.5a and 0.5a and got 3a+10=12.4. I subtracted 10 from both sides to get rid of it and got 3a=2.4. Later, I divided 3 from both sides to get a which comes out to be 0.8.

Hope this helps you :)

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8. Write an inverse variation equation relating x and y when x = 18 and y = 4.5. (64) help pliz

mr Goodwill [35]

Answer:

answer are

a.k=13.5;13.5y=x

b.k=1.5;y=1.5x

c.k=1.5;y=1.5/x

d.k=13.5;xy=13.5

3 0

3 years ago

A Statistics professor has observed that for several years students score an average of 106 points out of 150 on the semester ex

tekilochka [14]

Answer:

Step-by-step explanation:

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,

µ = 106

For the alternative hypothesis,

µ > 106

It is a right tailed test because of >.

Since no population standard deviation is given, the distribution is a student's t.

Since n = 241,

Degrees of freedom, df = n - 1 = 241 - 1 = 240

t = (x - µ)/(s/√n)

Where

x = sample mean = 109

µ = population mean = 106

s = samples standard deviation = 8.3

a) test statistic, t = (109 - 106)/(8.3/√241) = 5.61

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

p = 0.00001

Since alpha, 0.05 > than the p value, 0.00001, then we would reject the null hypothesis. Therefore, At a 5% level of significance, this improvement seem to be practicallysignificant.

b) Confidence interval is written in the form,

(Sample mean - margin of error, sample mean + margin of error)

The sample mean, x is the point estimate for the population mean.

Margin of error = z × s/√n

Where

s = sample standard deviation

n = number of samples

From the information given, the population standard deviation is unknown, hence, we would use the t distribution to find the z score

df = 240

Since confidence level = 95% = 0.95, α = 1 - CL = 1 – 0.95 = 0.05

α/2 = 0.05/2 = 0.025

the area to the right of z0.025 is 0.025 and the area to the left of z0.025 is 1 - 0.025 = 0.975

Looking at the t distribution table,

z = 1.6512

Margin of error = 1.6512 × 8.3/√241

= 0.88

Confidence interval = 109 ± 0.88

7 0

2 years ago

Ayo helppp ill give u anthing

kicyunya [14]

Answer:

16.9 m

Step-by-step explanation:

Start with a half a circle. The central angle of a semicircle is 180 deg.

Now subtract 21 deg on each side.

180 - 21 - 21 = 138

The central angle is 138 deg.

The radius is 7 m.

Now we use the formula for the length of an arc of a circle given the radius of the circle and the central angle of the arc.

$s = \dfrac{n}{360^\circ}2 \pi r$

$s = \dfrac{138^\circ}{360^\circ}2(3.14159)(7~m)$

$s = 16.9~m$

4 0

3 years ago

What is the answer please.... need help

mina [271]

Answer:

$f\left(x\right)=x^3-6x^2+3x+10$ is the function of the least degree has the real coefficients and the leading coefficients of 1 and with the zeros -1, 5, and 2.

Step-by-step explanation:

Given the function

$f\left(x\right)=x^3-6x^2+3x+10$

As the highest power of the x-variable is 3 with the leading coefficients of 1.

So, it is clear that the polynomial function of the least degree has the real coefficients and the leading coefficients of 1.

solving to get the zeros

$f\left(x\right)=x^3-6x^2+3x+10$

$0=x^3-6x^2+3x+10$ ∵ $f(x)=0$

$Factor\:x^3-6x^2+3x+10\::\:\left(x+1\right)\left(x-2\right)\left(x-5\right)=0$

$\left(x+1\right)\left(x-2\right)\left(x-5\right)=0$

Using the zero factor principle

if $ab=0\:\mathrm{then}\:a=0\:\mathrm{or}\:b=0\:\left(\mathrm{or\:both}\:a=0\:\mathrm{and}\:b=0\right)$

$x+1=0\quad \mathrm{or}\quad \:x-2=0\quad \mathrm{or}\quad \:x-5=0$

$x=-1,\:x=2,\:x=5$

Therefore, the zeros of the function are:

$x=-1,\:x=2,\:x=5$

$f\left(x\right)=x^3-6x^2+3x+10$ is the function of the least degree has the real coefficients and the leading coefficients of 1 and with the zeros -1, 5, and 2.

Therefore, the last option is true.

8 0

2 years ago

Which statement describes the function y = axn when a = 1 and n is odd?

kiruha [24]

Answer:

The graph is symmetric about the origin.

The graph does not pass through the origin.

Step-by-step explanation:

We're given:

the function y=axn
a = 1
n is odd

Because a = 1, then the given function can be rewritten as y = n.

The graph opens down

The function y = n will produce a horizontal line. Any function in the form of y = a single number, such as 4 or 9.3 will produce a horizontal line.

The graph is symmetric about the origin.

This is true, given the graph is a horizontal line.

The graph does not pass through the origin.

This is also true. We're given that n is an odd number. The graph will only pass through the origin if n = 0, and 0 is even.

The graph has more than one x-intercept.

This would only be true when n = 0, and this isn't possible. So, no.

4 0

2 years ago

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