**Sample Exam I Questions**

**MSC 287**

**Dr. Lovelace**

3. financial analyst is interested in the amount of resources spent by computer hardware and software companies on research and development (R&D). She sapmles 50 of these high-technology firms and calculates the amount each spent last year on R&D as a percentage of their total revenues. The results are given below.

13.5 |
8.0 |
8.2 |
9.6 |
7.1 |

8.4 |
7.9 |
8.0 |
7.2 |
13.2 |

10.5 |
6.8 |
7.7 |
8.8 |
7.7 |

9.0 |
9.5 |
7.4 |
11.3 |
5.9 |

9.2 |
8.1 |
6.5 |
8.5 |
5.2 |

9.7 |
13.5 |
9.5 |
9.4 |
5.6 |

6.6 |
9.9 |
8.2 |
10.5 |
11.7 |

10.6 |
6.9 |
6.9 |
6.9 |
6.0 |

10.1 |
7.5 |
7.2 |
6.5 |
7.8 |

7.1 |
11.1 |
8.2 |
7.5 |
6.5 |

For a frequency distribution of this data,

a. How many classes would you suggest? (5 pts.)

b. What would be the lower limit of the lowest class? (10 pts.)

c. What would be the upper limit of the highest class? (10 pts.)

d. What would be the class width? (10 pts.)

e. Construct a frequency distribution.

3. The Midland National Bank selected a sample
of 40 student checking accounts. Below
are their end-of-month balances. (The
data have already been put in order from smallest to largest for your
test-taking pleasure and convenience).

27 |
57 |
87 |
141 |
215 |
279 |
327 |
425 |
503 |
712 |

37 |
68 |
123 |
149 |
234 |
302 |
350 |
440 |
521 |
758 |

43 |
72 |
125 |
185 |
234 |
303 |
358 |
489 |
608 |
863 |

55 |
74 |
127 |
203 |
252 |
321 |
404 |
489 |
703 |
968 |

(a) Determine the first quartile (i.e., the 25^{th}
percentile) of the bank balance data.
(10 pts.)

4. Your height and weight are examples of which
level of measurement? (5
pts.)

a.
Nominal

b.
Ordinal

c.
Interval

d.
Ratio

e.
none of the
above

5. Shoe sizes, such as 7B, 10D, and 12EEE, are
examples of what level of measurement?
(5 pts.)

a.
Nominal

b.
Ordinal

c.
Interval

d.
Ratio

e.
none of the
above

1.
The U.S.
Department of Education reported that for the past six years 23, 19, 15, 30,
27, and 25 women per year received doctorate degrees in computer and
information sciences.

(a) Find the arithmetic mean number of women per year receiving
these degrees. (5 pts.)

(b) Find the standard
deviation of this data. (10 pts.)

1. Give an example of data whose point of
central tendency is best described by the median, not the mean. (Example:
home selling price). Tell *why* the median is superior to the mean
in your particular example. (10 pts.)

2.
For each of
the following, determine whether the group is a sample or a population.

a.
The 30 stocks
reported as a part of the Dow Jones Industrial Average. (2.5 pts.)

b. All
those incarcerated in the Limestone County Jail. (2.5 pts.)

c.
The ACT scores
of the freshmen class at

(2.5 pts.)

d.
The
participants in a study of a new cholesterol drug. (2.5

(2.5 pts.)