The following sample represents observation on viscosity of asphalt specimens: 2780, 2900, 3010, 2860, 2880.

A normal probability plot supports the assumption that viscosity has the normal distribution.

1) Estimate a 95% confidence interval for the true mean viscosity.

2) Estimate a 95% upper bound for the true mean viscosity.

3) Predict the viscosity for a single asphalt specimen with 90% confidence