Question

3.2 measures of spread: standard deviation and variance
to determine if reiki is an effective method for treating pain, a pilot study was carried out where a certified second - degree reiki therapist provided treatment on volunteers. pain was measured using a visual analogue scale (vas) immediately before and after the reiki treatment (olson & hanson, 1997) and the data for a random sample of volunteers were recorded. the vas readings before the reiki treatment had a mean of 3.89 and a standard deviation of 2.19 and vas readings after the reiki treatment had a mean of 2.04 and a standard deviation of 2.11.
which of the following statements best compares the means?
select an answer
which of the following statements best compares the standard deviations?
select an answer
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Explanation:

Step1: Compare the means

The mean before treatment is 3.89 and after is 2.04. Since 3.89 > 2.04, the mean pain level (VAS reading) before Reiki treatment is higher than the mean pain level after the treatment.

Step2: Compare the standard - deviations

The standard deviation before treatment is 2.19 and after is 2.11. Since 2.19>2.11, the data points for pain levels before Reiki treatment are more spread out than the data points for pain levels after the treatment.

Answer:

The mean pain level (VAS reading) before Reiki treatment is higher than the mean pain level after the treatment. The data points for pain levels before Reiki treatment are more spread out than the data points for pain levels after the treatment.