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12. Percentiles AaAa The following are weights (in pounds) for a sample of 11 ba

ID: 3060111 • Letter: 1

Question

12. Percentiles AaAa The following are weights (in pounds) for a sample of 11 baby boys at the age of 18 months: 21.8 22.2 23.424.6 25.1 26.7 27.3 28.0 29.8 30.9 31.2 The estimate for the 80th percentile for these sample data is frequency table-with the list of actual scores in the "X" column-and include a column of cumulative percentages. To calculate the percentile, you may need to interpolate between two cumulative percentages, keeping the upper real limits in mind.) pounds. (Hint: It may help to create a cumulative In the sample data, out of 11 observations are less than or equal to the 80th percentile, andout of 11 observations are greater than or equal to this value.

Explanation / Answer

80th Percentile

P80 = 80N/100) th observation = 80*11/100 =8.8th observation.

Since 8.8th observation lies between 8th and 9th observation of the arranged ( ascending order) data

P80 = 28+0.8(29.8-28) =29.44

The estimate for the 80th percentile for these sample data is 29.44 pounds

In the sample data, 8 out of 11 observations are less than or equal to 80th percentile and 3 out of 11 observations are greater than or equal to this value.