Question

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

Explanation:

Step1: Calculate the proportion of heads - up for the given data

We can find the proportion of heads - up for the last data point (90 flips, 45 heads - up). The proportion $p=\frac{45}{90}=\frac{1}{2}=0.5$.

Step2: Estimate for 100 flips

If the proportion of heads - up is 0.5, for 100 flips, the number of heads - up $n = 100\times0.5=50$.

Answer:

50