Lab 2 - Biometry work

MTH 280 - Biometry Lab 2 – Summary Statistics Population 100.0% maximum 72 99.5% 72 97.5% 72 90.0% 70 75.0% quartile 68.5 50.0% median 65 25.0% quartile 64 10.0% 62 2.5% 61 0.5% 61 0.0% minimum 61 Sample Mean 65.973684 Std Dev 3.1379119 Std Err Mean 0.7198864 Upper 95% Mean 67.486109 Lower 95% Mean 64.461259 N 19 N Missing 0 Mean 64.4 Std Dev 3.0495901 Std Err Mean 1.3638182 Upper 95% Mean 68.186566 Lower 95% Mean 60.613434 N 5 N Missing 0 100.0% maximum 68 99.5% 68 97.5% 68 90.0% 68 75.0% quartile 67.5 50.0% median 64 25.0% quartile 61.5 10.0% 61 2.5% 61 0.5% 61 0.0% minimum 61

1. For the height of the five randomly selected individuals, determine the sample mean and the sample median. Sample mean = 64.4 S ample median = 64 2. Compare and contrast the sample mean to the sample median . How close are the mean and median ? (Provide the actual difference between the two). Explain the reason(s) for the size of the difference if there is any. How useful is it to use a random sample of 5 individuals to represent the population? The sample median is the data located at the exact middle of the total observations (n). while the sample mean is an average of all the data. The mean and the median are close to a 0.4 difference. This difference is presented because the mean is an average of all data and if there are outliers or extreme values that can influence the mean. I don’t think a sample of 5 is a good representation of the population. 3. For the height of the population, determine the population mean and population median. Population mean = 65.9 Population median = 65 4. How well do the sample statistics estimate the population parameters ? In this case, there is not much difference. The values are closer to each other but for example, in a population, the max was 72 when in the sample size the max was 68. 5. What could we do to improve sample statistics’ estimation of population parameters ? Make sure that all the groups are represented and a min of 10 samples to represent a population.