A sample of 44 smartphone users found that on average they picked up their phones 34 times per day, with a standard deviation s=7.2. Construct a confidence interval at a 99% confidence level for the true mean number of times a smartphone user picks up their phone every day. Assume the data came from a normally distributed population. Give your answers to one decimal place.  < μ <

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.