In reference to the data sets above, please help me understand the following questions. Hoping for better understanding and clarification....

1. What is the mean return rate?
2. What is the standard deviation of the return rates? (I think this answer 5.58? Am I incorrect?)
3. Half of the mutual funds have return rates of at least what percent?
4. The top 10% of mutual funds have return rates of at least what percent?
5. The lowest 25% of mutual funds have return rates below what percent?

Measures of Central Tendency Measures of Dispersion Mean 31.36 Range 38.60 Median 30.50 Interquartile Range 4.50 Mode 30.50 Standard Deviation 5.58 Midrange 29.30 Variance 31.09 Coefficient of Variation 17.78% Other Measures Mean +/- 1 standard dev. 25.78 36.93 Sample Size 194 # Observations within 1 standard dev. 150 Minimum 10.00 Maximum 48.60 Mean +/- 2 standard dev. 20.21 42.51 First Quartile 28.45 # Observations within 2 standard dev. 176 Third Quartile 32.95 Mean +/- 3 standard dev. 14.63 48.09 Given percentile = 90% # Observations within 3 standard dev. 192 Value of percentile = 38.1