Suppose the temperature at 6pm was 30 f. What would the temperature have been

Change the recurring decimal into fraction, 3.256

BabaBlast [244]

Answer:

405 / 125

Step-by-step explanation:

3.256

= 3256 / 1000

= 407 / 125

5 0

3 years ago

The constant of proportionality can be found by finding the

KatRina [158]

Answer:

The constant of proportionality k is given by k=y/x where y and x are two quantities that are directly proportional to each other. Once you know the constant of proportionality you can find an equation representing the directly proportional relationship between x and y, namely y=kx, with your specific k.

6 0

2 years ago

Read 2 more answers

From a square piece of cardboard paper of area size 9 m2 , squares of the same size are cut off from each corner of the paper. T

levacccp [35]

Answer:

Max vol = 2 cubic metres

Step-by-step explanation:

Given that from a square piece of cardboard paper of area size 9 m2 , squares of the same size are cut off from each corner of the paper.

Side of the square = 3m

If squares are to be cut from the corners of the cardboard we have the dimensions of the box as

3-2x, 3-2x and x.

Hence x can never be greater than or equal to 1.5

V(x) = Volume = $V(x) = x(3-2x)^2\\= 9x+4x^3-12x^2$

We use derivative test to find the maxima

$V'(x) = 9+12x^2-24x\\V"(x) = 24x-24\\$

Equate I derivative to 0

$9+12x^2-24x=0\\x=1/2,3/2$

If x= 3/2 box will have 0 volume

So this is ignored

V"(1/2) <0

So maximum when x =1/2

Maximum volume

= $9(1/2)+4(1/2)^3-12(1/2)^2\\=2$ cubic metres

6 0

3 years ago

in a school gym, the ratio of the number of boys to the number of girls was 4:3 . after 160 boys left the gym, the ratio became

Annette [7]

Answer:

300 girls were there in the gym.

Step-by-step explanation:

Given:

The ratio of the number of boys to the number of girls was 4:3, after 160 boys left the gym, the ratio became 4:5.

Now, to find the number of girls in the gym.

The girls in the gym does not left, their quantity is same before and after.

So, we multiply the both ratios to make the girls ratio same:

4:3 × 5 = 20:15

4:5 × 3 = 12:15

Now, <em>we find the units of the ratio</em>.

<em>The ratio of boys dropped down by 160</em>:

20 - 12 = 8 units.

160 = 8 units

Now, dividing both sides by 8 we get:

20 = 1 unit

So, 1 unit = 20.

Now, girls = 15 units

So, 15 × 20 = 300.

Therefore, 300 girls were there in the gym.

3 0

3 years ago

An automobile dealer wants to see if there is a relationship between monthly sales and the interest rate. A random sample of 4 m

SVETLANKA909090 [29]

Answer:

a) $y=-6.254 x +75.064$

b) r =-0.932

The % of variation is given by the determination coefficient given by $r^2$ and on this case $-0.932^2 =0.8687$ , so then the % of variation explained by the linear model is 86.87%.

Step-by-step explanation:

Assuming the following dataset:

Monthly Sales (Y) Interest Rate (X)

22 9.2

20 7.6

10 10.4

45 5.3

Part a

And we want a linear model on this way y=mx+b, where m represent the slope and b the intercept. In order to find the slope we have this formula:

$m=\frac{S_{xy}}{S_{xx}}$

Where:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=278.65-\frac{32.5^2}{4}=14.5875$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i){n}}=696.9-\frac{32.5*97}{4}=-91.225$

And the slope would be:

$m=\frac{-91.225}{14.5875}=-6.254$

Nowe we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{32.5}{4}=8.125$

$\bar y= \frac{\sum y_i}{n}=\frac{97}{4}=24.25$

And we can find the intercept using this:

$b=\bar y -m \bar x=24.25-(-6.254*8.125)=75.064$

So the line would be given by:

$y=-6.254 x +75.064$

Part b

For this case we need to calculate the correlation coefficient given by:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

$r=\frac{4(696.9)-(32.5)(97)}{\sqrt{[4(278.65) -(32.5)^2][4(3009) -(97)^2]}}=-0.937$

So then the correlation coefficient would be r =-0.932

The % of variation is given by the determination coefficient given by $r^2$ and on this case $-0.932^2 =0.8687$ , so then the % of variation explained by the linear model is 86.87%.

6 0

3 years ago