Identify the factual error in each of the following three statements:

1. In any normal distribution of population values, the mean of the distribution plus or minus one standard deviation includes 25 percent of the area under the normal curve.

2. To avoid bias in the selection of a sample, every item must have a systematic (every "ith" item) chance of selection.

3. Assuming the same population size, sample size, and estimated error rate, an increase in the confidence level will result in a narrowing of the range of precision.