SPSS Project II
Michael J. Walk
APPL 631.185
4 October 2006
1)Breakfast Cereal Stem-and-Leaf / Box-and-Whisker Plot
a)See plot.
b)The interquartile range is: 3rd Q – 1st Q = 15.60 – 15.30 = 0.30
c)Interpretation of data:The middle 50% of the weights are between 15.30 and 15.60. Weights pile toward the upper end of the scale (the upper 75% of them are between 15.30 and 15.67 while the lower 25% are between 14.91 and 15.30). The median of 15.45 suggests that the cereal company is filling the boxes as hoped with only a few boxes having slightly less than 15 oz.
2)Hospital Stay Stem-and-Leaf / Box-and-Whisker Plot
a)See plot.
b)Suggestion to hospital:I would notify the hospital of the results by informing them of the 5-summary values for each case, pointing out that the middle 50% of scores fall between 3.5 and 7.5 days for Medical services and between 5.5 and 11 days for Surgical services. I would also point out that the longest length stay was the same in both conditions; however, it is an extreme score in the Medical condition.
c)Are the data sufficient?: The data do suggest that admission to the medical service reduces length of stay.
d)Why?: The data suggest a reduced stay mainly because of where the middle 50% of scores fall in each condition. By comparing the 3rd and 1st quartiles as well as the medians of each distribution, we can see at least a 2-day reduction (on average) in length of stay. It is also important to note that, while both conditions had 4 scores of 10 or greater, 15 of the scores in the Medical condition were below 10, while only 12 were below 10 in the Surgical condition (and 25% of those scores were 9).
3)Bar Graph – Coupon Life
a)Qualitative
b)Ordinal
c)See charts.
d)Although the differences between the two years would be easier to see on a grouped bar chart or two bar charts with equal Y-scales, by examining the data, it is possible to identify differences between the two graphs. Namely, in 2005, the most common coupon life was 5-8 months, creating a approximately symmetrical distribution with frequencies tapering off as they increase or decrease from the mode. In 2005, relatively few coupons lasted less than one month (frequency = 28). However, in 2006, the modal coupon life was 1-4 months (frequency = 140), with a relatively similar frequency of less than 1 month and 5-8 months coupons (frequency = 123 and 122, respectively). The 2006 distribution is clustered toward the lower end of the scale with only 115 coupons lasting 9 months or longer as compared to the 2005 distribution with 180 coupons. The data definitely suggest a change in coupon life.
4)Aggravated Assault Bar Graph
a)Victim’s age = Quantitative, … ratio scale (numeric discrete)
b)Although across both genders, the rate of assault decreases when age increases, there is a large difference between the assault rate on younger males and younger females. Younger males seem to be the most frequent victims of assault, especially between the ages of 15 and 21. The rate of male assault decreases and levels out from 30-49 years of age, then begins a steady decrease from 50 and above. Females are less likely to be the victims of assault, yet they are similar to the males the peak rates of assault are found between the ages of 15 and 21. After 21 years of age, the rate of female assaults steadily decreases into old age.