1. SSF1093 Exercise for Numerical presentation

2. Mark intervalMale (frequency)Female (frequency) 50-< than 601012 60-< than 7088 70 - < than 802025 80 - < than 100125 a.Calculate the mean marks for male and female students, respectively. b.What is the mean marks difference between boys and girls? c.Get the standard deviation mark for boys and girls. d.Which group has a more inequality (difference) in marks?

3. Using the information showed in frequency distribution table below, find (i) the mean time taken to finish a task, (ii) the standard deviation of time taken, (iii) what does 7 indicate in the second column?, (iv) determine the median time taken. Time takenfrequency 115 127 1510 2513 3016

4. Is the mean or the median a better measure (indicator) of central tendency for data set that have extreme values (outliers)? Illustrate with the help of an example. According to the Department of Statistics, the average annual salary of a worker in Penang is RM35748. Suppose the median annual salary for a worker in this group is RM31369 and the mode is RM29500. Is the distribution of salaries for this group is skewed? If so, how And why? Which of these measures of central tendency would you use to describe these data? Why?

5. The following table gives the frequency distribution of the time (in minutes) that 30 UNIMAS students spent looking for a parking spaces on the first day of classes in the semester 1 of 2012. Find the mean, variance and standard deviation. Are values of these summaries refer as parameter or statistic? Briefly explain. TimeNumber of students 0 to less than 45 4 to less than 88 8 to less than 1210 12 to less than 167

6. Data interpretation It appears that in all three grades the percentage of students that admitted to smoking tobacco was less in the year 2001 than it was in 1999. However, the reduction was greater in 7th graders (6% down to 3%) and in 9th graders (17% down to 13%) than in 11th graders which was at the highest of the three levels in 1999 at 23% and only decreased by one percent to 22% in 2001.

7. SexnMinQ1MedianQ3Max Female945963646670 Male775768707277

8. We can describe differences or similarities between the two sets of data such as follows. In general the males are taller than the females. For instance, the median height of males (70 inches) is greater than the median height of females (64 inches) and 75% of the men are taller than 68 inches, while 75% of the women are shorter than 66 inches. But, the low value for the males (57 inches) is less than the low value for the females (59 inches).