Find all real solutions of the equation by factoring calculator

A circle has an area of 144 cm2.Find the circumference

lara [203]

Circumference of Circle = 2πrArea of circle = πr²144 = 3.14 * r²r² = 144/3.14r² = 45.85r = √45.85r = 6.77 Circumference = 2πr = 2*3.14*6.77Circumference = 42.51 m²
So, your answer is 42.51 m²

5 0

3 years ago

8. In an examination 40% of the students failed. The number of students that passed was 180. How many students failed?

EastWind [94]

Answer:

Neither. 72 students failed.

Step-by-step explanation:

40% of 180 is 72

8 0

3 years ago

Read 2 more answers

Find an equation to the line perpendicular to 4x + 36y =80 an goes through the point (3,6) write answer in form y= Mx+b

Veronika [31]

Answer:

$\textbf{y = 9x + 21 }\\$

Step-by-step explanation:

$\textup{Given equation is: $4x + 36y = 80 $}\\\textup{This can be written in the form of $y = mx + a$ as follows}\\$ 36y = -4x + 80 $\\$ \implies y = \frac{80}{36} - \frac{4}{36}x $\\$ \implies y = \frac{-1}{9}x + \frac{20}{9} $\\\textup{This means that the slope of this line is $m = \frac{-1}{9}$}\\$

$\textup{Then the slope of the line perpendicular to this line would be \textbf{negative reciprocal of m}.}\\$i.e.,$ \textup{Slope of the perpendicular line would be $m_1 = \frac{-1}{\frac{-1}{9}}$}\\$\implies m_1 = 9$\\$

$\textup{The perpendicular line passes through the point $(3,6)$}\\\textup{Using the \textbf{point-slope formula}, we get:}\\$

$$$ y - y_1 = m(x - x_1) $$$ \implies y - 6 = 9(x - 3) $\\\textup{After solving this reduces to $y = 9x + 21$ }$

8 0

3 years ago

Suppose a baker claims that the average bread height is more than 15cm. Several of this customers do not believe him. To persuad

laila [671]

Answer:

$17-2.262\frac{1.9}{\sqrt{10}}=15.641$

$17+2.262\frac{1.9}{\sqrt{10}}=18.359$

So on this case the 95% confidence interval would be given by (15.641;18.359)

And since the lower limit for the confidence interval is higher than 15 we can conclude that at 5% of significance the true mean is higher than 15 cm

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".

$\bar X=17$ represent the sample mean

$\mu$ population mean (variable of interest)

s=1.9 represent the sample standard deviation

n=10 represent the sample size

Confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=10-1=9$

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(0.025,9)".And we see that $t_{\alpha/2}=2.262$

Now we have everything in order to replace into formula (1):

$17-2.262\frac{1.9}{\sqrt{10}}=15.641$

$17+2.262\frac{1.9}{\sqrt{10}}=18.359$

So on this case the 95% confidence interval would be given by (15.641;18.359)

And since the lower limit for the confidence interval is higher than 15 we can conclude that at 5% of significance the true mean is higher than 15 cm

4 0

3 years ago

A teacher divided students into groups of 3. Each group of 3 wrote a report that had 9 pictures in it. The students used 585 pic

jeyben [28]

So this is what i did but im not sure if its 100% correct

585 / 9 to get the number of groups = 65

then you take 65 x 3 for number of students in each group and you get the final answer of 195 students

5 0

3 years ago

Read 2 more answers