The speeds of vehicles traveling on a highway are normally distributed with an unknown population mean and standard deviation. Arandom sample of 11 vehicles is taken and results in a sample mean of 65 miles per hour and sample standard deviation of 9 miles per hour.

df...910111213t0.10...1.3831.3721.3631.3561.350t0.05...1.8331.8121.7961.7821.771t0.025...2.2622.2282.2012.1792.160t0.01...2.8212.7642.7182.6812.650t0.005...3.2503.1693.1063.0553.012

Find a 90% confidence interval estimate for the population mean using the Student's t-distribution.

• Round the final answers to two decimal places.