Answer:
The probability for a girl to be born is 0.4913. This technique doesnt appear to improve the likelihood of having a baby girl.
Explanation:
Since the number of babies selected for this technique, using the law of big numbers, we conclude that the proportion of babies that are girls in the selection is approximately equal than the probability for a girl to be selected. Thus, the probability that a girl will be born using the technique is 281/(281+291) = 0.4913.
Since in general girls are slightly more likely to be born than boys, then we can conclude that the technique doesnt have an effect in improving the likelihood of having a baby girl, but the opposite.