In this experiment, researchers placed a pair of lizards from Iron Cay, which has large trees, in an experimental island, which has only small bushes and grass. After several generations, they measured the leg length of 10 lizards from each site. Which group of lizards had longer legs on average?

A. The ones on Iron Cay

B. The ones on the experimental island

C. There is little or no difference between the two samples

D. The difference between the two samples is too large to be conclusive

On average, the lizards from Iron Cay seem to have longer legs than the lizards living on the experimental island. We know this because the sample means + 2 SEMs (the 95% confidence intervals) do not overlap. However, to know whether the difference between the means is statistically significant you would need to use a statistical test like the student t-test