Final answer:
The provided context does not include sufficient information to determine Bertha's account contributions. It details Freda and Frank's real estate equity and investments but lacks any data relating to Bertha's financial activities. Additional details about Bertha's investments would be necessary to provide an accurate answer.
Step-by-step explanation:
The question appears to be missing some information regarding Bertha's contributions to her account, as the context provided does not include details about Bertha's financial actions. Instead, the information provided includes the financial details of Freda and Frank's real estate purchases and equity situations.
For example, Freda bought a house for $150,000 in cash and if sold now, the value would be $250,000, which means her equity is $250,000 because she owes nothing to the bank. Whereas, Frank bought a house for $100,000, put 20% down, which is $20,000, and borrowed the remaining $80,000 from the bank. The house's value increased to $160,000, and since he paid off $20,000 of the loan, he now owes $60,000 to the bank making his equity $100,000 (the current value of $160,000 minus the owed amount of $60,000).
Without additional information on Bertha's contributions, it is impossible to answer the initial question about the amount contributed to her account. To ascertain Bertha's contribution, one would require data such as initial investment amounts, the rate of return, and the period of the investment, which are not provided.