Math worksheet focusing on solving problems with unknown bases or percents, including survey data, production statistics, and club membership calculations.

Final Answer:
595

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Explanation:
We are told that 40% of the people polled preferred the music of Mozart, and that 238 people preferred Mozart.

Let the total number of people polled be $ x $.
Then:
$$
40\% \text{ of } x = 238
$$
In math:
$$
0.40 \times x = 238
$$

To find $ x $, divide both sides by 0.40:
$$
x = \frac{238}{0.40} = \frac{238}{\frac{2}{5}} = 238 \times \frac{5}{2} = 119 \times 5 = 595
$$

So, 595 people were polled.