Unformatted text preview: Student: Grady Simonton
Instructor: Shawn Parvini Date: 2/18/10 Course: Math119: Elementary Statistics  Spring 2.010  CRN: 49239
 16 weeks Book: Triola: Elementary Statistics, 11e Time: 11:06 AMI The frequency distIibution below represents frequencies of
actual low temperatures recorded during the course of a
31day month. Use the frequency distribution to construct a
histogram. Do the data appear to have a distribution that is
approximately normal? class
A 39— 44 4
B 45  50 5
C 51  56 6
D 5? 62 3
E 63  68 4
F 69 74 5
G '75  80 4 The ﬁrst task is to use the frequency distribution to create a
histogram. A histogram is a bar graph in which the horizontal scale
represents classes of data values and the vertical scale
represents frequencies. The heights of the bars correspond
to the frequency values, and the bars are drawn adjacent to
each other (without gaps). This histogram represents the data. 10 0 ABCD EFG The next task is to decide whether the data appear to have
a distribution that is approximately normal. Key characteristics of the normal or "hell shape" are (1) the
rise in frequencies that reach a maximum, then decrease,
and (2) the symmetry with the left half of the graph that is
roughly a mirror image of the right half. If the graph does not appear to be normal, look at it to see
if the values are evenly distributed or skewed in a certain
direction. In this case, the frequencies do not match the description of
the normal curve since the data seems to be uniformly
distributed. Page 1 ...
View
Full Document
 Spring '10
 PARVINI

Click to edit the document details