Final answer:
The exact price of a Whataburger in 1964 cannot be determined without specific data, but it's likely that it was within the lower price range considering the general cost of living and prices of that era.
Step-by-step explanation:
The cost of a Whataburger in 1964 is not explicitly provided in the information given, but we can use the data as a reference to estimate the economy of the 1960s. Given the prices from the 1970 reference, like a gallon of gasoline being $0.36 and the average hourly wage for a manufacturing worker being $3.23, we can infer that the cost of living and prices were relatively low compared to today's standards.
Unfortunately, without specific data on the actual price of a Whataburger in 1964, we cannot determine the exact cost, and thus we cannot answer whether it was $0.25, $0.35, $0.45, or $0.55. However, considering the era's general price levels, it would be reasonable to assume that the price of a Whataburger could align with one of the lower-end options presented, such as $0.25 or $0.35.