Looking at higher confidence levels, if a woman wants to be 90% certain she'll receive a response from a man her own age, she'll have to send 13 messages. Finally, to be 99% certain she'll receive a response, a woman must send 25 messages to men her own age. This leads us to believe that one potential cause of the disparity between the male response rate and female response rate is the system itself.
We can't guarantee a response, per se, but we can say how confident we are that these average bachelors and bachelorettes will receive at least one response given the number of messages they send.
We know, from the chart above, that a woman who sends a message to a man her own age has a 17.5% likelihood of receiving a response to that message.
There are also alternative social theories for age differences in relationships as well as suggested reasons for 'alternative' age-hypogamous relationships.
Age-disparity relationships have been documented for most of recorded history and have been regarded with a wide range of attitudes dependant on sociocultural norms and legal systems.
So, we can see that women are much more selective than men when it comes to responding to messages.