A website claims that 10% of U.S. adults are left-handed. A researcher believes that this figure is too low. She decides to test this claim by taking a random sample of 20 U.S. adults and recording how many are left-handed. Four of the adults in the sample are left-handed. Does this result give convincing evidence that the website’s 10% claim is too low? To find out, we want to perform a simulation to estimate the probability of getting 4 or more left-handed people in a random sample of size 20 from a very large population in which 10% of the people are left-handed.

Let 00 to 09 indicate left-handed and 10 to 99 represent righthanded. Move left to right across a row in Table D. Each pair of digits represents one person. Keep going until you get 20 different pairs of digits. Record how many people in the simulated sample are left-handed. Repeat this process many, many times. Find the proportion of trials in which 4 or more people in the simulated sample were left-handed.

Determine whether the simulation design is valid. Justify your answer.