All categories

3 years ago

The length of a rectangle is four times its width.

Mathematics

1 answer:

s2008m [1.1K]3 years ago

5 0

Answer:

length 32 cm
width 8 cm

Step-by-step explanation:

Let w represent the width. Then the length is 4w and the perimeter is ...

P = 2(length +width)

80 = 2(4w +w) = 10w . . . . substitute given values

8 = w . . . . . . . divide by 10

length = 4w = 4·8 = 32

The length is 32 cm; the width is 8 cm.

You might be interested in

You spin the spinner and flip a coin. Find the probability of the compound event.

elena55 [62]

Answer:

Step-by-step explanation:

Even number on spinners are 5 out of 10 probability of it is 1/2 and probablity of coin landing on tails also 1/2

Probability of compound event is probability of first event multiplied by probability of second even

So 1/2×1/2=1/4

Second one is 9/10×1/2=9/20

8 0

3 years ago

The radius of a circle is 42 inches. What is the circle's area?<br> Use 3.14 for .

Mazyrski [523]

Answer:

A =5538.96 in^2

Step-by-step explanation:

The area of a circle is given by

A = pi r^2

We know the radius is 42 and pi is approximated by 3.14

A = 3.14 * 42^2

A =5538.96 in^2

3 0

3 years ago

Read 2 more answers

A regression analysis between sales (y in $1000) and advertising (x.in dollars) resulted in the following equation: ỹ= 30,000 +

Dafna11 [192]

Answer:

Correct answer is option d. increase of $1 in advertising is associated with an increase of $4000 in sales.

Step-by-step explanation:

Given the equation of regression analysis is given as:

$y= 30,000 + 4x$

where $x$ is the cost on advertising in Dollars.

and $y$ is the sales in Thousand Dollars.

To find:

The correct increase in sales when there is increase in the advertising cost.

Solution:

Suppose there is an increase of $\$1$ in the advertising cost.

Let the initial cost be $x$ then the cost will be $(x+1)$ .

Initial sales

$y= 30,000 + 4x$ ....... (1)

After increase of $1 in advertising cost, final cost:

$y'= 30,000 + 4(x+1)\\\Rightarrow y' = 30,000+4x+4\\\Rightarrow y' = 30,004+4x ..... (2)$

Subtracting (2) from (1) to find the increase in the sales:

$y'-y=30004+4x-30000-4x = 4$

The units of sales is Thousand Dollars ($1000).

So, increase in sales = $4 \times1000 = \bold{\$4000}$

So, correct answer is:

d. increase of $1 in advertising is associated with an increase of $4000 in sales.

7 0

3 years ago

What is the product of (x-2) (x-3)

Alja [10]

Answer: x^2 - 5x + 6

Step-by-step explanation: Expand the polynomial using the FOIL method.

3 0

3 years ago

Read 2 more answers

(23.01) In a randomized comparative experiment on the effect of dietary calcium on blood pressure, researchers divided 58 health

Paul [167]

Answer:

$113.7-2.154\frac{9.1}{\sqrt{29}}=110.06$

$113.7+2.154\frac{9.1}{\sqrt{29}}=117.34$

And the 96% confidence is given by (110.06; 117.34)

Step-by-step explanation:

Information given

$\bar X=113.7$ represent the sample mean

$\mu$ population mean (variable of interest)

s=9.1 represent the sample standard deviation

n=29 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)

The degrees of freedom are given by:

$df=n-1=29-1=28$

The Confidence is 0.96 or 96%, the significance is $\alpha=0.04$ and $\alpha/2 =0.02$ , and the critical value would be $t_{\alpha/2}=2.154$

Replacing the info we got:

$113.7-2.154\frac{9.1}{\sqrt{29}}=110.06$

$113.7+2.154\frac{9.1}{\sqrt{29}}=117.34$

And the 96% confidence is given by (110.06; 117.34)

5 0

4 years ago