# Project #23009 - statistics

need work shown if needed

1.   Determine if the following variables are categorical or numeric. In addition, if they are numeric, whether

they are  discrete or continuous.

Data Type                        Discrete/Continuous

a.       The temperature (in degrees Celsius) at

which each piece of heat-resistant plastic

begins to melt                                                               _________________        _________________

b.       The current unemployment rate (measured as

a percentage) for each of the 50 states                   _________________        _________________

c.        The defective status (defective or not) of

computer chips manufactured by Intel                  _________________        _________________

d.       The scores of  law school applicants on the

LSATs.                                                                          _________________        _________________

e.        Cyanide concentration (parts per million)

of the rivers in Romania                                            _________________        _________________

f.    Weights (in grams) of the fish caught by a

deep-sea fishing party                                                  _________________        _________________

g.   A taste-tester's ranking (best, worst, etc.) of

several brands of barbecue sauce                               _________________        _________________

h.   Number of convicted murderers who receive the

death penalty each year                                              _________________        _________________

i.         The size of a car (subcompact, mid-size, or

full-size) rented by business travelers                      _________________        _________________

j.         Number of census workers canvassing the city

for the 2000 federal census                                       _________________        _________________

2.       Thirty students in an experimental psychology class used various techniques to train a rat to move through a

maze. At the end of the course, each student's rat is timed through the maze.  The mean time that it took the rats

to traverse the maze was 13.7 seconds with a standard deviation of 2.2 seconds. Using the 68 - 95-99.7 Rule,

determine the following:

a.       What percentage of these rats made it through the maze in less than 9.3 seconds.

b.       What percentage took longer than 15.9 seconds?

c.        What is the probability that a particular rat took between 9.3 and 18.1 seconds?

d.       What percentage of the rats took between 7.1 and 20.3 seconds?

e.    What is the length time a particular rat took if only 2.5% of all times are shorter?

f.    How many of the rats took less than 7.1 seconds or more than 20.3 seconds?

3.       A manufacturer of computer work stations is investigating the down time of its systems. The 20 most recent

customers were  surveyed to determine the amount of down time (in hours) they had experienced during the previous month. The data is listed below.

12           16             5            16           21           29           38           14           47             0

24           15           13             8            2             11           22           16           31           10

a.       Construct an ordered stem-and-leaf plot for the data.

b.       Find the mean length of down time, the median and the mode for the data.

c.        Find the range, Q1 and Q3. What is the IQR for the data?

d.       Determine the Five Number Summary.

4.       A statistical analysis of 1,000 long distance telephone calls made from the headquarters of Johnson & Shurgot

Corporation indicates that the length of these calls is normally distributed with a mean of 240 seconds and a

standard deviation of 40 seconds.

e.        What percentage of these calls lasted less than 180 seconds?

f.        What percentage lasted longer than 300 seconds?

g.        What is the probability that a particular call lasted between 180 and 280 seconds?

h.       What percentage of the calls lasted between 110 and 180 seconds?

e.    What is the length of a particular call if only 1% of all calls are shorter?

f.    How many of the calls lasted less than 180 seconds or more than 300 seconds?

 Subject Mathematics Due By (Pacific Time) 02/16/2014 10:00 pm
TutorRating
pallavi

Chat Now!

out of 1971 reviews
amosmm

Chat Now!

out of 766 reviews
PhyzKyd

Chat Now!

out of 1164 reviews
rajdeep77

Chat Now!

out of 721 reviews
sctys

Chat Now!

out of 1600 reviews

Chat Now!

out of 770 reviews
topnotcher

Chat Now!

out of 766 reviews
XXXIAO

Chat Now!

out of 680 reviews