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2 years ago

9

Frank is practicing for a 5 km race his normal time is 31 minutes 17 seconds yesterday it took him only 29 minutes and 49 second

s how much faster with Frankie yesterday than his normal time

1 answer:

Vesna [10]2 years ago

6 0

Answer:

2 minutes and 8 seconds faster.

Step-by-step explanation:

Hope this hel;ps

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A square has a side of length of 12 centimeters. Which of he following is closest to the length of a diagonal of the square?

dimaraw [331]

<span>length of a diagonal of the square = </span>√(12^2 + 12^2)
= √(144 + 144)
= √288
= 16.97 cm

4 0

2 years ago

At the beginning of an environmental study, a forest covered an area of 1500km^2. Since then, the area has decreased by 6.3% eac

geniusboy [140]

The <em><u>correct answer</u></em> is:

$y=1500(0.937)^t$

Explanation:

An exponential function is of the form

$y=a\times b^x$ , where a is the initial population, b is 1 plus the amount of yearly change, and x is the number of years.

For our problem, a, the initial population, is 1500.

The yearly change is 6.3%; 6.3% = 6.3/100 = 0.063. Since it is decreasing, this is negative; 1+(-0.063) = 0.937.

We use t as the number of years.

This gives us

$y=1500(0.937)^t$

3 0

3 years ago

What is the equation of the best-fitting regression line? Find this in two ways. First, using the regression analysis part of th

Lemur [1.5K]

Step-by-step explanation:

Regression analysis is used to infer about the relationship between two or more variables.

The line of best fit is a straight line representing the regression equation on a scatter plot. The may pass through either some point or all points or none of the points.

<u>Method 1:</u>

Using regression analysis the line of best fit is: $y=\alpha +\beta x+e$

Here <em>α </em>= intercept, <em>β</em> = slope and <em>e</em> = error.

The formula to compute the intercept is:

$\alpha =\bar y-\beta \bar x$

Here<em> </em> $\bar y$ and $\bar x$ are mean of the <em>y</em> and <em>x</em> values respectively.

$\bar y=\frac{\sum y_{i}}{n} \\\bar x=\frac{\sum x_{i}}{n}$

The formula to compute the slope is:

$\beta =\frac{\sum (x-\bar x)(y - \bar y)}{\sum (x=\bar x)^{2}}$

And the formula to compute the error is:

$e=y-\alpha -\beta x$

<u>Method 2:</u>

The regression line can be determined using the descriptive statistics mean, standard deviation and correlation.

The equation of the line of best fit is:

$(y-\bar y)=r\frac{\sigma_{x}}{\sigma_{y}} (x-\bar x)$

Here <em>r</em> = correlation coefficient = $r=\frac{Cov (x,y)}{\sqrt{\sigma^{2}_{x}\sigma^{2}_{y}} }$

$\sigma_{x}$ and $\sigma_{y}$ are standard deviation of <em>x</em> and <em>y</em> respectively.

$\sigma_{x}=\frac{1}{n}\sum (x-\bar x)^{2} \\\sigma_{y}=\frac{1}{n}\sum (y-\bar y)^{2}$

3 0

3 years ago

Enter the numerator and the denominator of the fraction in simplest form that is equal to 0.7 repeating

valentinak56 [21]

Answer:

$\frac{7}{9\\}$

Step-by-step explanation:

8 0

1 year ago

4y= -6x +8 <br>find the y-intercept

ivanzaharov [21]

First, divide each side by 4 to get y alone on the left side.

y=-6/4x+2

The y intercept is 2

7 0

3 years ago