Chapter 5, Problem 37A

Interpretation Introduction

Interpretation: The conversion factor that is appropriate to express the cost of 5.3 lb of apples to be calculated.

Concept introduction: Scientific notation is quantitative information is called a measurement and exists of a number and a unit. By using scientific notation too large or too small numbers are conveniently expressed.

Answer to Problem 37A

Cost of 5.3 lb of apples is $\text{4}\text{.187\$}$ .

Explanation of Solution

Significant figures are first uncertain number plus all certain numbers.

Given 1lb of apples = $0.79.

Conversion factor of this statement is as follows:

  $\frac{\text{1lb}}{\$0.79}\text{or}\frac{\$0.79}{\text{1}\text{lb}}$

Second conversion factor is acceptable because it will cause quantity of pounds to be cancelled, allowing final cost to be quantified.

Conversion of 1849 to miles is as follows:

  $\text{5}\text{.3}\cancel{\text{lb}}\text{×}\frac{\$0.79}{\text{1 }\cancel{\text{lb}}}\text{=4}\text{.187\$}$

Cost of 5.3 lb of apples is $\text{4}\text{.187\$}$ .

Conclusion

Inherent uncertainty of the measuring device determines number of significant figures for a given measurement.