Categorical Or Quantitative Variables, Histogram, Pie-Chart And Bar Graph Worksheet (Page 2 of 3) in pdf

Categorical Or Quantitative Variables, Histogram, Pie-Chart And Bar Graph Worksheet Page 2

8. A student received the following grades on quizzes in a history course: 80, 88,

75, 93, 79, 95, 75, and 96.

Find the mean, and median, and the ﬁrst and second quartiles of this data.

Also compute the standard deviation.

9. Suppose that the weight of a molar is normal with mean 30mg and standard

deviation 4mg. What portion of molars weigh on average will more than 31mg?

10. To make a knife, a steel blank has to be cut so that it is longer than 7 inches

but shorter than 7.3 inches. Suppose the length of steel blanks which are man-

ufactured follows a normal distribution with mean 7.25 inches and a standard

deviation of

of an inch. What portion of the blanks manufactured on average

will meet these speciﬁcations?

11. The wingspan of a falcon in feet follows a N(3.3,.1) distribution. What portion

of observations of the wingspan of falcons do you expect to ﬁnd between 3.1

and 3.5 feet?

12. The wingspan of a falcon in feet follows a N(3.3,.1) distribution. How large

must a bird’s wingspan be in order to place it in the top 10% of all falcons?

13. A circus is recruiting chimpanzees for a show, and they want the chimpanzees

to be either really tall, or really short. The heights of monkeys follow a normal

distribution with mean 4 feet and standard deviation 6 inches. If the circus

purchases a whole barrel of chimps, what portion do you expect to have heights

larger than 5 feet and smaller than 3 feet 7 inches?

14. The data below relates the weights of fruitﬂys (in micro grams) to the number

Fruit Fly Weight Number of oﬀspring

of oﬀspring they produce.

(a) Create a scatter plot for this data.

(b) Does the data exhibit a positive or negative association?

15. Suppose that the heights and shoe sizes are measured of a sample of men from

the University. It is found that the mean height of this sample is 6 feet with a

standard deviation of .5 feet, and that the mean shoe size is a 10 with a standard

Categorical Or Quantitative Variables, Histogram, Pie-Chart And Bar Graph Worksheet Page 2