Answer: The correct option is 5.7/20 = x/200
Step-by-step explanation: Please refer to the diagram attached for more details.
From the 7-column by 2-row table drawn, you can determine that the mean number of catfish as given in the question is derived as follows;
Mean = Summation of observed data / Number of observations
Mean = (3 + 5 + 7 + 5 + 6 + 8)/6
Mean = 34/6
Mean = 5.6667
Mean ≈ 5.7
Also the mean number of all fish is derived as follows;
Mean = Summation of observed data / Number of observations
Mean = (20 + 20 + 20 + 20 + 20 + 20)/6
Mean = 120/6
Mean = 20
Using relative frequency, we can confidently predict the number of catfish population in the pond. This simply means, if the mean number of catfish is 5.7 and the mean number of all fish is 20, then the relative frequency would be 5.7 over 20 of the total fish population.
Hence, if there is a total of 200 fish in the pond then to predict the proportion which would be catfish can be expressed as follows;
StartFraction 5.7 over 20 EndFraction = StartFraction x over 200 EndFraction.
OR better expressed as;
5.7/20 = x/200