Basic Technical Mathematics, 11th Edition

CHAPTER 22 REVIEW EXERCISES

CONCEPT CHECK EXERCISES

Determine each of the following as being either true or false. If it is false, explain why.

1. If the raw data includes 25 values, and a class includes 3 of these values, the relative frequency of this class is 12%.

2. The mean of the numbers 2, 3, 6, 4, 5 is 4.

3. The standard deviation of the numbers 2, 3, 6, 4, 5 is $\sqrt{\mathrm{5/2}}$.

4. For a normal distribution for which $\mu \hspace{0.17em}=\hspace{0.17em}10$ and $\sigma \hspace{0.17em}=\hspace{0.17em}5\hspace{0.17em},\hspace{0.17em}$ the z-scores for $x\hspace{0.17em}=\hspace{0.17em}20$ and $x\hspace{0.17em}=\hspace{0.17em}30$ are $z\hspace{0.17em}=\hspace{0.17em}1.5$ and $z\hspace{0.17em}=\hspace{0.17em}\mathrm{2.5.}$

5. If the least-squares line for a set of data is $y\hspace{0.17em}=\hspace{0.17em}2x\hspace{0.17em}+\hspace{0.17em}4\hspace{0.17em},\hspace{0.17em}$ the deviation of the data point (2, 6) is 4.

6. In linear regression, a value of r close to 0 indicates a good fit.

PRACTICE AND APPLICATIONS

In Exercises 7–14, use the following data. An airline’s records ...