Sampling then write the topic by your own - Assignment Example

Sampling Part One In the first sample, the first 20 were considered because each of them is equally representative and that they were easily available. Convenience sampling technique comes in handy due the fact that data can easily be collected and analyzed. A major disadvantage is that sometimes it fails to represent the total population (Thompson 14). Another disadvantage of this method is that respondents may be biased. This could amount to accidental sampling. The ids of the students picked were as follows: Id12345678910Days absent 01311413251Id11121314151617181920Days absent 21311431138The number of days absent was fewer.

In the second sample, students were picked randomly; the first and the last ten students were considered. The students were chosen as follows: Id12345678910Days absent 01311413251Id919293949596979899100Days absent 07846103438The average was: 84/20= 4.2; this number was closer to the average than the previous sampling method. By taking the first ten students and the last ten students, the sample was almost evenly distributed.Systematic SampleId12345678910Days absent 01311413251Id919293949596979899100Days absent 07846103438Here, the students were chosen systematically.

The sample of students picked were those falling between ids 21 to 40. This was because the number of days absent was evenly distributed. Again, there was need for an average that is closed to the total population’s average. Id21222324252627282930Days absent 5115101134369Id31323334353637383940Days absent 142441256165Average number of students absent: 126/20=6.3; this number was higher than the total average. This is due to the fact that the sample chosen represented the highest number of absentees.

Overall, the three different sampling techniques had the following advantages and disadvantages:Convenient samples can easily be assessed; they are not involving. In this sampling technique, data is easily gathered and analyzed. A major risk associated with this method is that it is not representative of the whole population (Thompson p16). Respondents can sometimes be biased. Moreover, there may be overrepresentation and underrepresentation of some members of the sample.Simple random sampling has a major advantage; respondents are selected randomly, so the results may be close to average.

Every segment has an equal probability of being chosen. It reduces biases associated with overrepresentation and underrepresentation (Thompson p24). A major disadvantage of this method is that all members of the population may have to be listed; which could be quite cumbersome and time consuming. Systematic sampling uses fixed intervals with a stated staring point. It has the same advantages and disadvantages as simple random sampling. In all the three sampling techniques, the sample interval was ten.

Part Two (A)The sampling interval in this second part is ten.Below are the five simple random samples considered: 5-24; 25-44; 45-64; 65-84; 81-100.Id567891011121314Days absent 14132512131Id15161718192021222324Days absent 1431138511510Average: 94/20=4.7; lower than the average.Id25262728293031323334Days absent 113436914244Id35363738394041424344Days absent 12561655924Average: 115/20=5.75; slightly greater than the average.Id45464748495051525354Days absent 754061551134Id55565758596061626364Days absent 41317934119155Average: 150/20=7.

5; greater than the average. Id65666768697071727374Days absent 10712053148512Id75767778798081828384Days absent 56008345211Average: 120/20=6; greater than the average.Id81828384858687888990Days absent 452119996103Id919293949596979899100Days absent 07846103438Average: 133/20=6.65; greater than the average. The average number of absentees is distributed around the mean for the total; in some samples, the average is slightly higher; in some samples, it is slightly lower. Specify your six different estimates of absenteeism.

How do they compare to the population value? How much variation do you observe across your six samples? The greatest variation is (7.5-5.95) = 1.65; the least is (5.95-5.75) =0.20.Part B 2The samples will be taken at the following intervals:1-40; 11-50; 21-60; 31-70; 41-80; 51-90Id1234567891011121314151617181920Days Absent 0131141325121311431138Id2122232425262728293031323334353637383940Days Absent5115101134369142441256165Average: 194/40= 4.85.Id1112131415161718192021222324252627282930Days Absent 213114311385115101134369Id3132333435363738394041424344454647484950Days Absent14244125616559247540615Average: 220/40=5.

5Id2122232425262728293031323334353637383940Days Absent 5115101134369142441256165Id4142434445464748495051525354555657585960Days Absent592475406155113441317934Average: 268/40=6.7Id3132333435363738394041424344454647484950Days Absent 14244125616559247540615Id5152535455565758596061626364656667686970Days Absent511344131793411915510712053Average: 266/40=6.65Id4142434445464748495051525354555657585960Days Absent 592475406155113441317934Id6162636465666768697071727374757677787980Days Absent11915510712053148512560083Average: 278/40=6.

7Id5152535455565758596061626364656667686970Days Absent 511344131793411915510712053Id7172737475767778798081828384858687888990Days Absent1485121560083452119996103Average: 289/40= 7.1When a larger number is considered (40 instead of 20), the variation reduces. The average values are closer to the average for the total than when a sample of 20 is used. For instance, the largest variation is 7.1-5.85=1.25, and the smallest is 5.85-5.5=0.3. Larger samples have less variation. They give better results, which mean the average are closer to the whole population’s average.

It leads to generalization of the whole population (Thompson 34). Systematic sampling improves estimates since it representative samples are considered for best estimates. Work CitedThompson, Steven K. Sampling. Hoboken, N.J: Wiley, 2012.