Given Information:
- Twenty three brown bats were captured, marked, and released.
- One week later, 29 bats were captured.
- Out of the 29 captured bats, 11 had been marked.

Calculating the Estimated Population:
To estimate the population of bats, we can use the mark-recapture method. This method assumes that the proportion of marked bats in the second capture is equal to the proportion of marked bats in the entire population.

Step 1: Calculate the Capture-Recapture Ratio:
The capture-recapture ratio (R) can be calculated using the following formula:
R = (Number of individuals in the first capture * Number of individuals in the second capture) / Number of marked individuals in the second capture

In this case, the first capture involved 23 bats, the second capture involved 29 bats, and 11 of the bats in the second capture were marked.
R = (23 * 29) / 11
R ≈ 60.54

Step 2: Calculate the Estimated Population:
The estimated population (N) can be calculated using the following formula:
N = (Number of individuals in the first capture * Number of individuals in the second capture) / Number of marked individuals in the second capture

In this case, the first capture involved 23 bats, the second capture involved 29 bats, and 11 of the bats in the second capture were marked.
N = (23 * 29) / 11
N ≈ 60.54

Therefore, the estimated population of bats is approximately 60.54.

Answer Explanation:
The estimated population is given as a range between 60.5 and 60.7, which indicates that the true population size is likely to fall within this range. Since we rounded the value of N to two decimal places, the range indicates the uncertainty associated with the estimation process. It is important to note that this method assumes certain conditions, such as the assumption of equal probabilities of capture for marked and unmarked bats, no births, deaths, or migrations during the study period, and random mixing of the population. Violations of these assumptions can affect the accuracy of the estimation.