Answer:
166.9 miles per hour
Explanation:
To round a number to the nearest tenth, look at the next place value to the right (the hundredths). If it's 4 or less, just remove all the digits to the right. If it's 5 or greater, add 1 to the digit in the tenths place, and then remove all the digits to the right. Then, the answer is 166.9.