Final answer:
The calculated monthly water consumption for the Ivanov family is 3 tgal, which yields an annual estimate of 36 tgal. However, this figure does not match any of the provided options, indicating a possible typo in the question or options.
Step-by-step explanation:
To calculate the estimated annual water usage for the Ivanov family, we need to find out the monthly water consumption first and then multiply it by 12 to get the yearly estimate. The water reading for August is 5,619 tgal, and for September, it is 5,622 tgal. By subtracting the August reading from the September reading, we get the water usage for one month.
September reading - August reading = 5,622 tgal - 5,619 tgal = 3 tgal.
This is the consumption for one month, so to find the estimated annual consumption, we multiply this figure by 12, which represents the number of months in a year.
Monthly consumption × Number of months in a year = 3 tgal × 12 = 36 tgal annually.
However, the question appears to have a typo, as the consumption figures seem much smaller than expected for an annual estimation. Based on the options provided, all are too high for the calculated monthly usage. Thus, assuming a typo in the provided readings, the closest approximation to a realistic annual usage, based on the calculations done with the provided readings, is not present in the options.