Answer:
The correct option is B
Step-by-step explanation:
The formula for confidence interval for the mean is
Where, μ is population mean, σ is standard deviation, n is sample size and z* is z-score at given confidence interval.
From the z-table the value of z-score at 98% confidence interval is 2.33.
From the given information it is clear that
The 98% confidence interval for the mean hours devoted to social networking in January is
Therefore the 98% confidence interval ranges from 48.60 to 51.40 hours. Option B is correct.