Back to Fit data to a normal distribution — Problem 4 · Task Set 4

Exercises: Fitting Data to a Normal Distribution

Work through each section in order. For empirical-rule problems, use the
68-95-99.7 percentages and the curve's symmetry. For z-score problems, first
standardize with $z = \frac{x - \text{mean}}{\text{SD}}$ , then look up the
area with a calculator, spreadsheet, or table. Round percentages as directed.
Remember: the empirical rule and z-scores apply ONLY to roughly normal data.

Grade 10·21 problems·~35 min·Common Core Math - HS Statistics and Probability·group·hss-id-a-4

Work through problems with immediate feedback

Fluency Practice

Use the empirical rule and z-scores. Test scores below are normal with mean 500, SD 100.

Test scores are normal with mean $500$ , SD $100$ . Compute the z-score for a score of $x = 420$ . Enter the z-score (it may be negative).