Ask question

Ask question

All categories

3 years ago

12

an 8 by 19 ft wall has three 4 by 5 ft windows.the area of the three windows is what percent of the area of the entire wall (inc

luding the windows)?

1 answer:

erica [24]3 years ago

4 0

Answer:

39.5% (3 sf)

Step-by-step explanation:

Area of 1 window: 4×5 = 20 ft²

2 windows: 3×20 = 60ft²

Area of the wall: 8×19 = 152 ft³

Percentage of window area:

60/152 × 100 = 39.47368421%

= 39.5% (3 sf)

You might be interested in

Find the compound Interest for Rs.18,800 ,calculated for 2 years at 13% rate of Interest compounded annually

Vinvika [58]

For compound interest, the formula is given below:

Amount = $P(1+\frac{r}{100} )^{n}$

Here, P = 18,800

n = 2

r = 13/100

So, Amount = $18,800(1+\frac{13}{100} )^{2}$

$18,800(1.13)^{2}$

= 18,800 × 1.2769

= 24005.72

Compound Interest = Amount - Principal

Compound Interest = 24005.72 - 18800

= 5205.72

Hence, the compound interest for Rs.18,800, calculated for 2 years at 13% rate of interest compounded annually is Rs.5205.72.

4 0

3 years ago

With a height of 68 in, Nelson was the shortest president of a particular club in the past century. The club presidents of the

Ivahew [28]

Answer:

a. The positive difference between Nelson's height and the population mean is: $\\ \lvert 68-70.7 \rvert = \lvert 70.7-68 \rvert\;in = 2.7\;in$ .

b. The difference found in part (a) is 1.174 standard deviations from the mean (without taking into account if the height is above or below the mean).

c. Nelson's z-score: $\\ z = -1.1739 \approx -1.174$ (Nelson's height is <em>below</em> the population's mean 1.174 standard deviations units).

d. Nelson's height is <em>usual</em> since $\\ -2 < -1.174 < 2$ .

Step-by-step explanation:

The key concept to answer this question is the z-score. A <em>z-score</em> "tells us" the distance from the population's mean of a raw score in <em>standard deviation</em> units. A <em>positive value</em> for a z-score indicates that the raw score is <em>above</em> the population mean, whereas a <em>negative value</em> tells us that the raw score is <em>below</em> the population mean. The formula to obtain this <em>z-score</em> is as follows:

$\\ z = \frac{x - \mu}{\sigma}$ [1]

Where

$\\ z$ is the <em>z-score</em>.

$\\ \mu$ is the <em>population mean</em>.

$\\ \sigma$ is the <em>population standard deviation</em>.

From the question, we have that:

Nelson's height is 68 in. In this case, the raw score is 68 in $\\ x = 68$ in.
$\\ \mu = 70.7$ in.
$\\ \sigma = 2.3$ in.

With all this information, we are ready to answer the next questions:

a. What is the positive difference between Nelson's height and the mean?

The positive difference between Nelson's height and the population mean is (taking the absolute value for this difference):

$\\ \lvert 68-70.7 \rvert = \lvert 70.7-68 \rvert\;in = 2.7\;in$ .

That is, <em>the positive difference is 2.7 in</em>.

b. How many standard deviations is that [the difference found in part (a)]?

To find how many <em>standard deviations</em> is that, we need to divide that difference by the <em>population standard deviation</em>. That is:

$\\ \frac{2.7\;in}{2.3\;in} \approx 1.1739 \approx 1.174$

In words, the difference found in part (a) is 1.174 <em>standard deviations</em> from the mean. Notice that we are not taking into account here if the raw score, <em>x,</em> is <em>below</em> or <em>above</em> the mean.

c. Convert Nelson's height to a z score.

Using formula [1], we have

$\\ z = \frac{x - \mu}{\sigma}$

$\\ z = \frac{68\;in - 70.7\;in}{2.3\;in}$

$\\ z = \frac{-2.7\;in}{2.3\;in}$

$\\ z = -1.1739 \approx -1.174$

This z-score "tells us" that Nelson's height is <em>1.174 standard deviations</em> <em>below</em> the population mean (notice the negative symbol in the above result), i.e., Nelson's height is <em>below</em> the mean for heights in the club presidents of the past century 1.174 standard deviations units.

d. If we consider "usual" heights to be those that convert to z scores between minus2 and 2, is Nelson's height usual or unusual?

Carefully looking at Nelson's height, we notice that it is between those z-scores, because:

$\\ -2 < z_{Nelson} < 2$

$\\ -2 < -1.174 < 2$

Then, Nelson's height is <em>usual</em> according to that statement.

7 0

3 years ago

A window in the shape of a parallelogram has a base of 28 inches and a height of 71 inches. What is the area of the window?

Norma-Jean [14]

The area of the window is 1988 inches

6 0

3 years ago

A box of colored crayons contains 16 distinct colors. In how many ways can 14 colors be chosen, assuming that the order of the c

Harrizon [31]

Could you rephrase that? Is it just 14 multiplied by 14?

6 0

3 years ago

Read 2 more answers

I need help finding the range and domain, you can use the images I've included for guidance! I need this asap thank youu

SCORPION-xisa [38]

Answer:

$\displaystyle Range: \\ Set-Builder\:Notation → y|1 ≥ y ≥ -1 \\ Interval\:Notation → [-1, 1] \\ \\ Domain: \\ Set-Builder\:Notation → x|x ∈ R \\ Interval\:Notation → (-∞, ∞)$

Step-by-step explanation:

This is the graph of $\displaystyle y = cos\:x,$ in which its AMPLITUDE [<em>A</em>] ALWAYS starts ONE BLOCK ABOVE the <em>midline</em><em>.</em><em> </em>In the trigonometric formula below, −C gives the OPPOSITE terms of what they really are, so be EXTREMELY CAREFUL:

$\displaystyle y = Acos[Bx - C] + D$

NOTE: Depending on how your trigonometric graphs are structured, your vertical shift [<em>D</em>] might tell you to space out the amplitude of the graphs alot more evenly on both ends.

<u>Extended</u><u> </u><u>Information on</u><u> </u><u>Trigonometric</u><u> </u><u>Graphs</u>

$\displaystyle Vertical\:Shift = D \\ Phase\:Shift\:[Horizontal\:Shift] = \frac{C}{B} \\ Period = \frac{2}{B}π \\ Amplitude = |A|$

I am joyous to assist you anytime.

7 0

3 years ago