|STAT 13 (1a,
1b, 1c, 1d)
Methods for the Life and Health Science
|Department of Statistics
Instructor: Ivo Dinov
|Due Date: Wednesday, Jan. 18, 2012
(a) Construct a stem-and-leaf
diagram of the data by hand
(only for the RELIG, religiosity, variable)
(b) Construct a dotplot
the data, using SOCR
, for these variables - EDU, QOL, HI.
- (HW_1.3) The
histogram below (right) shows the same data that are shown in one of
boxplots (left). Which boxplot goes with the histogram? Explain!
- (HW_1.4) Dopamine is a
chemical that plays a role in the transmission of signals in the brain.
A pharmacologist measured the amount of dopamine in the brain of each
of seven rats. The dopamine levels (nmol/g) were as follows:
(a) Calculate the (sample) mean and
standard deviation. Explain these 2 sample measures in the context of
(b) Determine the median and the interquartile range.
(c) Calculate the coefficient
(d) Replace the observation 5.9 by 8.6 and repeat parts (a) and (b).
Which of the descriptive (sample) measures above display resistance to
this change and which do not?
- (HW_1.5) Using the
multivariate dataset on iris sepal and petal length dataset:
(a) Determine the median and the quartiles for the Sepal-Length(cm) of
the Iris-setosa genus.
(b) Determine the interquartile range of the Sepal-Length(cm) of the
(c) Construct a boxplot of the Sepal_Length, Sepal_Width, Petal_Length,
Petal_Width for each of the 3 genera, use SOCR Charts (Select
- (HW_1.6) A geneticist counted the number of
bristles on a certain
region of the abdomen of the fruitfly Drosophila
melanogaster. The results for 119 individual fruitflies
are shown in the table below.
(a) Find the Median number of
(b) Find Q1
(c) Make a histogram
of the number of bristles.
(d) Suppose the sample (number of
bristles) mean is 38.45 and the sample SD is 3.20. What percentage
of the observations fall within 1 SD of the mean?