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The last digits of the heights of a sample of people are tabulated along with their respective frequencies.

The observed frequency corresponding to a particular digit is the same as the frequency tabulated in the question.

Thus, the observed frequency for digit 7 is equal to 27.

The expected frequency corresponding to any digit is computed using the given formula:

\(E = \frac{n}{k}\)

where

n is the sum of all frequencies

k is the number of digits given

The sum of all frequencies is equal to:

\(\begin{aligned}{c}n = 30 + 35 + ......24\\ = 300\end{aligned}\)

The number of digits considered (k) is equal to 10.

Thus, the expected frequency for the last digit of 7 (same for all digits) is computed as follows:

\(\begin{aligned}{c}E = \frac{n}{k}\\ = \frac{{300}}{{10}}\\ = 30\end{aligned}\)

Therefore, the expected frequency for the last digit of 7 is equal to 30.