A random sample of 20 chocolate energy bars of a certain brand has, on average, 220 calories per bar, with a standard deviation of 35 calories. Construct a 90% confidence interval for the true mean calorie content of this brand of energy bar. Assume that the distribution of the calorie content is approximately normal. Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table. Click here to view page 1 of the table of critical values of the t-distribution. Click here to view page 2 of the table of critical values of the t-distribution.