All categories

3 years ago

Hi! If you can, please help me with this question. And show the steps on how you got your answer. Thank you!

Mathematics

1 answer:

Sergeeva-Olga [200]3 years ago

6 0

<h3>Answer: 35.5</h3>

===============================

Explanation:

The triangles are identical. So this means that the triangle on the left has the horizontal portion of 50 ft, and the other sides are x ft (where x is a placeholder for a number).

Add up the sides for the either triangle. We have x+x+50 = 2x+50. This expression is the perimeter of one triangle. The perimeter of both triangles is simply us doubling that expression

combined perimeter of 2 triangles = 2*(perimeter of one triangle)

combined perimeter of 2 triangles = 2*(2x+50)

combined perimeter of 2 triangles = 2*(2x)+2*(50) ... distribute

combined perimeter of 2 triangles = 4x+100

We're told that the combined perimeters total 242 ft, so this means 4x+100 must equal 242

Solve for x

4x+100 = 242

4x+100-100 = 242-100 ... subtract 100 from both sides

4x = 142

4x/4 = 142/4 ... divide both sides by 4

x = 35.5

note: 35.5 feet = 35 feet, 6 inches because 1/2 ft = 0.5 ft = (0.5*12) inches = 6 inches

You might be interested in

Please help me please

baherus [9]

Answer:

The answer is C

4 0

3 years ago

We considered the differences between the temperature readings in January 1 of 1968 and 2008 at 51 locations in the continental

mr Goodwill [35]

Answer:

$1.1-2.02\frac{4.9}{\sqrt{50}}=-0.30$

$1.1+2.02\frac{4.9}{\sqrt{50}}=2.50$

So on this case the 90% confidence interval would be given by (-0.30;2.50)

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".

$\bar X=1.1$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=4.9 represent the sample standard deviation

n=51 represent the sample size

Solution to the problem

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:

$df=n-1=51-1=50$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.05,50)".And we see that $t_{\alpha/2}=2.02$