Need help understanding these statistic problems with mean and standard deviation

These problems are highly confusing to me. I feel like there’s supposed to be a chart, but I can’t figure out which chart I’m looking for because my book has so many and my teacher did not give us the page number for these specific problems. I’m not asking anyone to solve them, just an explanation or the chart!

According to the Maryland Sentencing Commission, offenders convicted of first degree burglary receive a mean prison sentence of 7.9, with a population standard deviatior of 5.3. What percent of inmates were sentenced more than 12 years?

According to the Maryland Sentencing Commission, offenders convicted of first degree burglary receive a mean prison sentence of 7.9, with a population standard deviation of 5.3. What percent of inmates were sentenced between 2 and 5 years?