samples confidence intervals needed is Option C 136.
According to the Empirical rule, if data exists normally distributed then about 68% of the population lies within one standard deviation from the mean.
We assume that the mean of a normally distributed population exists at 300, and 200 simple random samples exist drawn from the population.
Number of simple random samples, n= 200
By Empirical rule, approximately 68% of 200 samples’ confidence intervals we would expect to have the population mean.
Required number of samples = 68% of 200
= 0.68 x 200 = 136
The required number of samples = 136
Therefore, the correct answer is option C) 136.
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