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2 years ago

14

Billy runs a miles in seven minutes and 30 seconds. For every mile Billy runs, he adds 30 seconds to his mile time. If Billy run

s EIGHT miles, how many minutes will it take him?

2 answers:

Whitepunk [10]2 years ago

6 0

Answer:

After the last lap it will take him 11 min to complete the lap and over all his time was 1 hour 14 min.

Step-by-step explanation:

Lap 1: 7:30

Lap 2: 8:00

Lap 3: 8:30

Lap 4: 9:00

Lap 5: 9:30

Lap 6: 10:00

Lap 7: 10:30

Lap 8: 11:00

= 74:00 = 1 hour 14 min

PLZ THANK AND 5 STAR AND GIVE BRAINLIEST :)

Tresset [83]2 years ago

5 0

Answer I don't know the answer but I just want to say I hope you do well!

Step-by-step explanation:

You might be interested in

Philip ran 4 3/8 miles yesterday. Michael ran 1 5/8 miles yesterday.

deff fn [24]

Answer:

2 7/8

Step-by-step explanation:

3 0

3 years ago

$85 jeans, 7% tax what is the total cost<br>please a show work

fgiga [73]

Answer:

<em>See below.</em>

Step-by-step explanation:

Divide to turn the percentage into a decimal.

$\frac{7}{100} =0.07$

Multiply to find the total amount of tax.

$85*0.07=5.95$

Add it to the total.

$85+5.95=90.95$

<em>Answer: </em> $90.95$ <em />

<em />

<em>:)</em>

8 0

3 years ago

Read 2 more answers

An experiment was conducted to observe the effect of an increase in temperature on the potency of an antibiotic. Three 1-ounce p

ludmilkaskok [199]

Answer:

a) $y=-0.317 x +46.02$

b) Figure attached

c) $S^2=\hat \sigma^2=MSE=\frac{190.33}{10}=19.03$

Step-by-step explanation:

We assume that th data is this one:

x: 30, 30, 30, 50, 50, 50, 70,70, 70,90,90,90

y: 38, 43, 29, 32, 26, 33, 19, 27, 23, 14, 19, 21.

a) Find the least-squares line appropriate for this data.

For this case we need to calculate the slope with the following formula:

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

Where:

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

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

So we can find the sums like this:

$\sum_{i=1}^n x_i = 30+30+30+50+50+50+70+70+70+90+90+90=720$

$\sum_{i=1}^n y_i =38+43+29+32+26+33+19+27+23+14+19+21=324$

$\sum_{i=1}^n x^2_i =30^2+30^2+30^2+50^2+50^2+50^2+70^2+70^2+70^2+90^2+90^2+90^2=49200$

$\sum_{i=1}^n y^2_i =38^2+43^2+29^2+32^2+26^2+33^2+19^2+27^2+23^2+14^2+19^2+21^2=9540$

$\sum_{i=1}^n x_i y_i =30*38+30*43+30*29+50*32+50*26+50*33+70*19+70*27+70*23+90*14+90*19+90*21=17540$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=49200-\frac{720^2}{12}=6000$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}=17540-\frac{720*324}{12}{12}=-1900$

And the slope would be:

$m=-\frac{1900}{6000}=-0.317$

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

$\bar x= \frac{\sum x_i}{n}=\frac{720}{12}=60$

$\bar y= \frac{\sum y_i}{n}=\frac{324}{12}=27$

And we can find the intercept using this:

$b=\bar y -m \bar x=27-(-0.317*60)=46.02$

So the line would be given by:

$y=-0.317 x +46.02$

b) Plot the points and graph the line as a check on your calculations.

For this case we can use excel and we got the figure attached as the result.

c) Calculate S^2

In oder to calculate S^2 we need to calculate the MSE, or the mean square error. And is given by this formula:

$MSE=\frac{SSE}{df_{E}}$

The degred of freedom for the error are given by:

$df_{E}=n-2=12-2=10$

We can calculate:

$S_{y}=\sum_{i=1}^n y^2_i -\frac{(\sum_{i=1}^n y_i)^2}{n}=9540-\frac{324^2}{12}=792$

And now we can calculate the sum of squares for the regression given by:

$SSR=\frac{S^2_{xy}}{S_{xx}}=\frac{(-1900)^2}{6000}=601.67$

We have that SST= SSR+SSE, and then SSE=SST-SSR= 792-601.67=190.33[/tex]

So then :

$S^2=\hat \sigma^2=MSE=\frac{190.33}{10}=19.03$

5 0

2 years ago

The linear function that is represented by which table has the same slope as the graph? On a coordinate plane, a line goes throu

lions [1.4K]

Answer:

c

step-by-step explanation:

ok the slope of the line is 2

and so by using the formula y1+y2/x1+x2 we can get the ration of each table

the first table is -9+-7/-25+-21

this can be simplified to -16/-46 which is about 0.347

using this formula for each table you can find the answer .

im

too lazy to do the rest

6 0

3 years ago

Read 2 more answers

Each state imposes its own excise tax on gasoline. Suppose, for example, that the state of Massachusetts imposes a state gasolin

vovangra [49]

Complete question :

Each state imposes its own excise tax on gasoline. Suppose, for example, that the state of Massachusetts imposes a state gasoline tax of $0.26 per gallon. Suppose further that an average of 1,022,000 gallons of gasoline per day were sold in Massachusetts in 2010. The average revenue from gasoline tax in 2010 is approximately?

Answer:

$265,720

Step-by-step explanation:

Given that:

State gasoline tax = $0.26 per gallon

Average number of gasoline sold per day = 1,022,000 gallons

. From the availabke information given :

Revenue generated = gasoline tax per gallon multiplied by the average number of gallons sold

= $0.26 * 1,022,000

= $265,720

3 0

3 years ago