Answer: 1
Explanation:
An expanded frequency distribution for a random sample of measurements can be used to construct a histogram.
For example, if there are 46 random measurements, the sorted data can be grouped into 8 bins, and the number of occurrences occurrence of the data within each bin will indicate the frequency. A histogram such as the one shown will describe the frequency distribution.
When each frequency is divided by the sample size, the relative frequencies define the probability density function.
The area under the curve (or the sum of the relative frequencies) should be equal to 1 because a probability of 1 defines the maximum value obtainable.