Answer:
Distance problems are word problems that involve the distance an object will travel at a certain average rate for a given period of time.
The formula for distance problems is: distance = rate × time or d = r × t.
Things to watch out for:
Make sure that you change the units when necessary. For example, if the rate is given in miles per hour and the time is given in minutes then change the units appropriately.
It would be helpful to use a table to organize the information for distance problems. A table helps you to think about one number at a time instead being confused by the question.
Step-by-step explanation:
<u>Answer-</u>
Correlation coefficient for the data in the table was found to be 0.93.
<u>Solution-</u>
Taking the independent variable or input variable as, the time a patient spends at the dentist and the dependent variable or output variable as the amount of the bill.
We know that,
![r=\frac{n(\sum xy)-\sum x \sum y}{\sqrt{[n\sum x^{2} -({\sum x})^{2}]\times [n\sum y^{2} -({\sum y})^{2}]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7Bn%28%5Csum%20xy%29-%5Csum%20x%20%5Csum%20y%7D%7B%5Csqrt%7B%5Bn%5Csum%20x%5E%7B2%7D%20-%28%7B%5Csum%20x%7D%29%5E%7B2%7D%5D%5Ctimes%20%5Bn%5Csum%20y%5E%7B2%7D%20-%28%7B%5Csum%20y%7D%29%5E%7B2%7D%5D%7D%7D)
Calculating the values from the table, then putting it in the formula
![r=\frac{4 \times 3130.9 \ - \ 6.45 \times 1473}{\sqrt{[4\times 12.3725 \ - \ 6.45^{2}][4 \times 877475 \ - \ 1473^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B4%20%5Ctimes%203130.9%20%5C%20-%20%5C%206.45%20%5Ctimes%201473%7D%7B%5Csqrt%7B%5B4%5Ctimes%2012.3725%20%5C%20-%20%5C%206.45%5E%7B2%7D%5D%5B4%20%5Ctimes%20877475%20%5C%20-%20%5C%201473%5E2%5D%7D%7D)
∴ Correlation coefficient for the data is 0.93.
do you want to know for the multipaction and subtraction and addition
Well, the first thing we need to do is divide 10 by 4. These teo numbers are the number of pens, and cost of them. So,
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10 / 4 = 2.5
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Now we have to use the answer we got, 2.5 which is the cost of 1 pen, and multiply it by 7.
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2.5 x 7 = 17.5
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This means that 7 pens cost <span>£</span>17.5
