The average survival time after diagnosis for a certain type of cancer on the standard treatment is two years. A medical researcher is working on a new treatment. In an early trial, she tries the new treatment on three subjects, who have an average survival time after diagnosis of four years. Although the survival time doubled, the results are not statistically significant, even at the 0.10 significance level, because: the calculation was in error; the researchers forgot to include the sample size. the placebo effect is present, which limits statistical significance. although the survival time has doubled, the actual increase is really two years. the sample size is small.