Answer:
The electric field is 
Explanation:
Given that,
Radius = 0.357 m
Charge 
Point charge 
Distance = 0.815 m
We need to calculate the total electric field
Using formula of electric field

Where, q = point charge
r = distance
Put the value into the formula


Hence, The electric field is 
Yes you can, with using scientific experiment.
Ask a question -- Do background Research -- Construct a Hypothesis --Test with an Experiment -- Procedure working? -- Yes or no? -- Analyze Data and Draw Conclusions
With an experiment you can discover if its correct or not.
Hope this helps ! <3