MS 150 Statistics summer 2007 Mx • Name:
Joggling
time/min 
2.77 
2.86 
2.86 
2.81 
2.81 
2.82 
2.82 
2.80 
2.88 
2.91 
2.88 
2.92 
2.67 
2.76 
2.69 
2.64 
2.66 
Part I: Basic statistics, frequencies, histogram, zscores, normal distribution.
Last night I went out and ran a midsummer's night seventeen joggling laps at the track. I timed each lap. Use my lap times for this first part of the test.
 __________ What level of measurement is the data?
 __________ Find the sample size n for the data.
 __________ Find the minimum.
 __________ Find the maximum.
 __________ Find the range.
 __________ Find the median.
 __________ Find the mode.
 __________ Find the sample mean x.
 __________ Find the sample standard deviation sx.
 __________ Find the sample coefficient of variation CV.
 __________ If this data were to be divided into four bins, what would be the width of a single bin?
 Determine the frequency and calculate the relative frequency using four bins. Record your results in the table provided.
Frequency table
Bins (x)  Frequency (f)  Rel. Freq. p(x) 
_______  _______  _______ 
_______  _______  _______ 
_______  _______  _______ 
_______  _______  _______ 
Sum: 
_______  _______ 
 Sketch a frequency histogram chart of the data here or on the back, labeling your horizontal axis and vertical axis as appropriate.
 ____________________ What is the shape of the distribution?
 ____________________ Use the mean ” and standard deviation σ calculated above to determine the zscore for the 2.92 minute lap.
 ____________________ Does the 2.92 minute lap have an ordinary or unusual zscore?
 ____________________ Bearing in mind that higher lap times are slower laps and slower speeds. Was my speed unusually low as measured by zscore?
 ____________________ Use the mean ” and standard deviation σ calculated above to determine the lap time which would have a zscore equal to negative two. Any lap time less than this value would be an unusually fast lap (low times are fast laps).
Part II: Linear regression
LRC: Building H
Month  Month number (x)  Power/KwH (y) 
Oct 06  10  24100 
Nov 06  11  26800 
Dec 06  12  26300 
Jan 07  13  20400 
Feb 07  14  26000 
Mar 07  15  17500 
Apr 07  16  27700 
May 07  17  23400 
On Thursday maintenance released their semiannual energy audit spreadsheet. The building that uses the most power is the Learning Resource Center. The table provides power consumption data in kilowatthours (KwH). For comparison purposes, my own home uses about 290 KwH per month.
 __________ Calculate the slope of the linear trend line for the data.
 __________ Calculate the yintercept for the data.
 __________ Is the correlation positive, negative, or neutral?
 __________ Determine the correlation coefficient r.
 __________ Is the correlation none, low, moderate, high, or perfect?
 __________ Does the relationship appear to be linear or nonlinear?
 __________ What is the projected power consumption a year from now in month number 41?
 __________ What month number had a power consumption of 25918 KwH?
Table of statistical functions used by OpenOffice
Statistic or Parameter  Symbol  Equations  OpenOffice 
Square root    =SQRT(number) 
Sample mean  x 
Σx/n  =AVERAGE(data) 
Sample standard deviation  sx   =STDEV(data) 
Sample Coefficient of Variation  CV  sx/
x 
=STDEV(data)/AVERAGE(data) 
Calculate a z value from an x  z  ^{=}

=STANDARDIZE(x;μ;σ) 
Slope  b   =SLOPE(y data;x data) 
Intercept  a   =INTERCEPT(y data;x data) 
Correlation  r   =CORREL(y data;x data) 