A research analyst was directed to arrange raw data collected on the yield of wheat, ranging from 40 to 93 bushels per acre, in a frequency distribution. He should choose 30 as the class interval width.（
举一反三
- In the market research phase, research is either primary or secondary research, which of the following ones are primary research data? A: Data collected from surveys B: Data collected from feedback C: Data collected from library D: Data collected from journal
- When constructing a frequency distribution, classes should be selected so that they are of equal width.
- True or False: When constructing a frequency distribution, classes should be selected so that they are of equal width.
- The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developed. Class Interval Frequency 20-under 40 30 40-under 60 45 60-
- In a frequency distribution histogram, the frequency of an interval is given by the:（） A: width of the corresponding bar. B: height multiplied by the width of the corresponding bar. C: height of the corresponding bar.