Applied Statistics Module
A sampling error denotes the poor representation of the population’s characteristics in the chosen sample. It is the discrepancy between the population parameter and the values of the sample statistic (Walker and Maddan, 2009). Thus, the higher the degree of sampling error committed, the less accurate the resulting sample; that is, the attributes which can be observed and quantified through the sample may not probably be true for the entire population. 2. No, the study utilized the survey method in data gathering.
The researchers mailed the questionnaires to the respective respondents, then, the self-report alcohol-use was evaluated through the returned mails. On the other hand, the experimental method requires at the two groups of respondents: the experimental and the control groups. Further, a set of experimental procedure will be done to the experimental group under controlled conditions while the control group will only be subjected to the natural-course of life. Observations will be taken from both groups and compared in order to determine the behavioral difference of each group under normal and controlled conditions.
. Based on the graph, the respondents can remember both humorous and nonhumorous statements. Ten respondents remembered more humorous sentences than nonhumorous statements while only three respondents remembered more nonhumorous sentences than humorous statements. In addition, three respondents can remember both humorous and nonhumorous sentences in the same frequency. Hence, it can be inferred that humor has influence on memory recall. 7. Explain what is meant by each of the following statements: a.
The mean is described as the “balance point” of the distribution because the number of observations above the mean is just equal to the total observations below it (Walker and Maddan, 2009). That is, the mean is always located inside the group of data; there will always be at least one data above the mean and another data below it. b. The median is defined as the midpoint of the distribution because it is the exact midpoint or the value that divides the distribution into two equal parts. 8. When the distribution is symmetrical, the value for mean, median, and mode is just the same.
9. Mean = ? fx/N N = 20 and Mean = 6 ?fx = 120, if another score, x = 27, will be added, then N = 21 and ? fx = 147 The new mean then: Mean = 147/21 = 7 10. Does it ever seem to you that the weather is nice during the work week, but lousy on the weekend? Cerveny and Balling (1988) have confirmed that this is not your imagination-pollution accumulating during the work week most likely spoils the weekend weather for people on the Atlantic coast. Consider the following hypothetical data showing the daily amount of rainfall for 10 weeks during the summer.
11. A sample of n=20 scores has a mean of M=30. a. No, the score x = 38 is still included in the distribution. By calculating its deviation from the mean, M = 30, the value of x-M (38-30) is 8. Since the sample standard deviation is 10 and the score deviation for x = 38 is 8, the score then is within the distribution. b. In this case, the score deviation is still 8 but the standard deviation of the sample is 2. Therefore, the score is out in the tail of the distribution. 12. A normal shaped population has a mean of µ=80 and a standard deviation of ?
=20. a. Since ? (X+C) where c is a constant, is just equal to ? X + ? C, then the mean will be increased by the value of the constant while the standard deviation will remain the same. Since the same value was added to each score, the scattering or clustering of scores was not affected. Therefore: µ = 80 + 10 = 90 and ? = 20. b. Since ? (X*C), where c is a constant, is equal to ? X multiply by C or c? x, both mean and standard deviation are multiplied to the constant. Hence, µ = 80 x 2 = 160 and ? = 20 x 2 = 40.Sample Essay of Paperial.com