Question

In a certain article, laser therapy was discussed as a useful alternative to drugs in pain management of chronically ill patients. To measure pain threshold, a machine was used that delivered low-voltage direct current to different parts of the body (wrist, neck, and back). The machine measured current in milliamperes (mA). The pretreatment experimental group in the study had an average threshold of pain (pain was first detectable) at μ = 3.02 mA with standard deviation σ = 1.29 mA. Assume that the distribution of threshold pain, measured in milliamperes, is symmetrical and more or less mound-shaped. (Round your answers to two decimal places.)

(a) Use the empirical rule to estimate a range of milliamperes centered about the mean in which about 68% of the experimental group will have a threshold of pain from                       mA to                         mA

Answer 1

Result:

In a certain article, laser therapy was discussed as a useful alternative to drugs in pain management of chronically ill patients. To measure pain threshold, a machine was used that delivered low-voltage direct current to different parts of the body (wrist, neck, and back). The machine measured current in milliamperes (mA). The pretreatment experimental group in the study had an average threshold of pain (pain was first detectable) at μ = 3.02 mA with standard deviation σ = 1.29 mA. Assume that the distribution of threshold pain, measured in milliamperes, is symmetrical and more or less mound-shaped. (Round your answers to two decimal places.)

(a) Use the empirical rule to estimate a range of milliamperes centered about the mean in which about 68% of the experimental group will have a threshold of pain from 1.73 mA 4.31 mA

The 68-95-99 empirical rule states that about 68% of all scores fall within one standard deviation of the mean, 95% of all scores fall within about 2 standard deviations of the mean and 99.7% of all scores fall within 3 standard deviations from the mean. This only works for data that is approximately bell shaped.

Since our data is symmetrical and more or less mound-shaped, empirical rule applies.

68% of the data fall within one standard deviation of the mean.

Mean -1sd = 3.02-1*1.29 = 1.73

Mean +1sd = 3.02+1*1.29 = 4.31