lydia runs an experiment to determine if a coin is fair by counting the number of times a coin lands heads…

lydia runs an experiment to determine if a coin is fair by counting the number of times a coin lands heads up. the table shows her data. coin fairness test number of coin flips 0 10 20 30 40 50 60 70 80 90 number of heads up 0 7 12 18 23 30 35 38 42 45 according to the line of best fit, about how many times would the coin land heads up in 100 flips? 48 50 51 53
Answer
Explanation:
Step1: Assume a linear relationship
Let the number of coin - flips be $x$ and the number of heads - up be $y$. We can use the two - point form of a line $y - y_1=\frac{y_2 - y_1}{x_2 - x_1}(x - x_1)$. Let's take two points from the data, say $(10,7)$ and $(90,45)$.
Step2: Calculate the slope
The slope $m=\frac{45 - 7}{90 - 10}=\frac{38}{80}=0.475$.
Step3: Use the point - slope form with the point $(10,7)$
The equation of the line is $y - 7=0.475(x - 10)$.
Step4: Expand the equation
$y-7 = 0.475x-4.75$, so $y=0.475x + 2.25$.
Step5: Substitute $x = 100$
When $x = 100$, $y=0.475\times100+2.25=47.5 + 2.25=49.75\approx50$.
Answer:
50