According to a survey, the average American person is in a car for 5 hours per week. To test if the amount of car time in Los Angeles is less than the national average, a researcher decides to hypothesis test, at a 10% significance level. She surveys 15 Los Angeleans randomly and asks them about their amount of time in a car each week, on average. From the data, the sample mean time is 4.3 hours per week, and the sample standard deviation (s) is 0.7 hours.

• H0: 5; Ha: >5.
• =0.1 (significance level)

What is the test statistic (t-value) of this one-mean hypothesis test (with unknown)?

• Round your final answer to two decimal places.