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2 years ago

6

Sue charges a flat rate of $20 plus $10 per hour it takes her to mow a lawn. Which equation shows the correct way to find the co

st y of mowing a lawn for x hours.

1 answer:

Nookie1986 [14]2 years ago

3 0

Answer:

y=20+10x

Step-by-step explanation:

From the information provided, the equation would indicate that the cost of mowing a lawn would be equal to the flat rate plus the result of multiplying the cost per hour for the number of hours:

y=20+10x, where:

y is the cost of mowing a lawn

x is the number of hours

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Without multiplying determine the sign of the product (-468,256)(183,758).

maxonik [38]

Answer:

negative

Step-by-step explanation:

rules:

+ + = +

- - = +

+ - = -

- + = - ----> (-468,256)(183,758)

3 0

2 years ago

#10 i The table shows the admission costs (in dollars) and the average number of daily visitors at an amusement park each the pa

lions [1.4K]

The line of best fit is a straight line that can be used to predict the

average daily attendance for a given admission cost.

Correct responses:

The equation of best fit is; $\underline{ \hat Y = 1,042 - 4.9 \cdot X_i}$

The correlation coefficient is; r ≈<u> -0.969</u>

<h3>Methods by which the line of best fit is found</h3>

The given data is presented in the following tabular format;

$\begin{tabular}{|c|c|c|c|c|c|c|c|c|}Cost, (dollars), x&20&21&22&24&25&27&28&30\\Daily attendance, y&940&935&940&925&920&905&910&890\end{array}\right]$

The equation of the line of best fit is given by the regression line

equation as follows;

$\hat Y = \mathbf{b_0 + b_1 \cdot X_i}$

Where;

$\hat Y$ = Predicted value of the<em> i</em>th observation

b₀ = Estimated regression equation intercept

b₁ = The estimate of the slope regression equation

$X_i$ = The <em>i</em>th observed value

$b_1 = \mathbf{\dfrac{\sum (X - \overline X) \cdot (Y - \overline Y) }{\sum \left(X - \overline X \right)^2}}$

$\overline X$ = 24.625

$\overline Y$ = 960.625

$\mathbf{\sum(X - \overline X) \cdot (Y - \overline Y)} = -433.125$

$\mathbf{\sum(X - \overline X)^2} = 87.875$

Therefore;

$b_1 = \mathbf{\dfrac{-433.125}{87.875}} \approx -4.9289$

Therefore;

The slope given to the nearest tenth is b₁ ≈ -4.9

$b_0 = \mathbf{\dfrac{\left(\sum Y \right) \cdot \left(\sum X^2 \right) - \left(\sum X \right) \cdot \left(\sum X \cdot Y\right)} {n \cdot \left(\sum X^2\right) - \left(\sum X \right)^2}}$

By using MS Excel, we have;

n = 8

∑X = 197

∑Y = 7365

∑X² = 4939

∑Y² = 6782675

∑X·Y = 180930

(∑X)² = 38809

Therefore;

$b_0 = \dfrac{7365 \times 4939-197 \times 180930}{8 \times 4939 - 38809} \approx \mathbf{1041.9986}$

The y-intercept given to the nearest tenth is b₀ ≈ 1,042

The equation of the line of best fit is therefore;

$\underline{\hat Y = 1042 - 4.9 \cdot X_i}$

The correlation coefficient is given by the formula;

$\displaystyle r = \mathbf{\dfrac{\sum \left(X_i - \overline X) \cdot \left(Y - \overline Y \right)}{ \sqrt{\sum \left(X_i - \overline X \right)^2 \cdot \sum \left(Y_i - \overline Y \right)^2} }}$

Where;

$\sqrt{\sum \left(X - \overline X \right)^2 \times \sum \left(Y - \overline Y \right)^2} = \mathbf{446.8121}$

$\sum \left(X_i - \overline X \right) \times \left(Y - \overline Y\right) = \mathbf{-433.125}$

Which gives;

$r = \dfrac{-433.125}{446.8121} \approx \mathbf{-0.969367213}$

The correlation coefficient given to the nearest thousandth is therefore;

<u>Correlation coefficient, r ≈ -0.969</u>

Learn more about regression analysis here:

brainly.com/question/14279500

7 0

2 years ago

Another fair dice is rolled 300 times. How many times would you expect it to land with a multiple of three on top? I need help t

ira [324]

Answer:

100 times

Step-by-step explanation:

multiples of 3 on a number cube are 3 and 6

probability of rolling a '3' or '6' is 1/6 + 1/6 = 2/6 or 1/3

1/3 x 300 = 100

7 0

3 years ago

In your biology class, your nal grade is based on several things: a lab score, scores on two major tests, and your score on the

Mariana [72]

Complete Question

In your biology class, your final grade is based on several things: a lab score, scores on two major tests, and your score on the final exam. There are 100 points available for each score. However, the lab score is worth 25% of your total grade, each major test is worth 22:5%, and the final exam is worth 30%. Compute the weighted average for the following scores: 92 on the lab, 81 on the first major test, 93 on the second major test, and 85 on the final exam. (Enter your answer to one decimal place)

Answer:

The weighted average is $W = 87.65$

Step-by-step explanation:

From the question we are told that

The worth of the lab score is 25% of total grade

The worth of each major test is 22.5% of total grade

The worth of final exam is 30% of total grade

The score on lab is 92

The score on first major test 81

The score on second major test 93

The score on final exam is 85

Generally the weighted score is mathematically represented as

$W = 0.25 * 92 + 0.225* 81 + 0.225* 93 +0.30 * 85$

=> $W = 0.25 * 92 + 0.225* 81 + 0.225* 93 +0.30 * 85$

=> $W = 87.65$

3 0

3 years ago

There are 1,295 students attending a small university.There are 714 women enrolled.What percent of the students are women?

BARSIC [14]

Total students = 1295

Number of women = 714

Percentage of women = 714/1295 x 100 = 55.14%

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Answer: 55.14% of the students are women.
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3 0

3 years ago