Step 1: Understanding the Concept
For \(y=A\sin 2\pi ft\), the angular frequency is \(\omega=2\pi f\). Beats per second equal \(f_1-f_2\).
Step 2: Beat frequency
\(f_1=\dfrac{710\pi}{2\pi}=355\text{ Hz}\) and \(f_2=\dfrac{702\pi}{2\pi}=351\text{ Hz}\), so beats per second \(=4\).
Step 3: Intensity ratio
Intensity is proportional to amplitude squared. Maximum amplitude is \(4+3=7\) and minimum is \(4-3=1\).
Step 4: Result
\(\dfrac{I_{max}}{I_{min}}=\dfrac{7^2}{1^2}=49:1\).
Final Answer:
There are 4 beats per second and the intensity ratio is 49:1.
\[ \boxed{\text{(C) }4,\ 49:1} \]