Chinenye G. answered • 10/01/20
Chemistry and Statistics tutor
For normal distribution or bell curve data, 68 percent of the data lie within one standard deviation of the mean, 95 percent lie within 2 standard deviations of the mean, and 99.7 percent of the data lie within 3 standard deviations of the mean. What you must do is figure out what and how these numbers correspond to where they are (or how far they are from the mean) and figure out what percentage of the data lie in between them. What you will need to do is calculate the z score and find what percentage is associated with each z score. The equation is: z= x- mew/sd. Mew refers to the greek symbol for mean, sd is the standard deviation. So applying this we would have for the first data value: (22-46)/12 = -2. The second value: (70-46)/12 = 2. So with these z-score of -2 and 2 it is indicating that this percentage is within 2 standard deviations from the mean, -2 referring to the area below the mean, and 2 referring to the area above the mean. Using the emperical formula (68-95-99.7) 95 % of the data lie within these parameters. So you can say that 95% of the data lie between the data values 22 and 70.
