Short Answer 
The process involves identifying various ratios of miles to hours, calculating their unit rates, and then determining which rates exceed 1. The ratios that have a unit rate greater than 1 are a) 4 miles : 3 1/3 hours, c) 9/8 miles : 5/6 hour, d) 9/5 miles : 3 hours, e) 2 1/2 miles : 3 hours, and f) 7 miles : 3/4 hour.
Step 1: Identify the Ratios
Start by listing the ratios you need to evaluate for their unit rates. The ratios in question are:
- a) 4 miles : 3 1/3 hours
- b) 1/3 mile : 2 3/8 hours
- c) 9/8 miles : 5/6 hour
- d) 9/5 miles : 3 hours
- e) 2 1/2 miles : 3 hours
- f) 7 miles : 3/4 hour
Step 2: Calculate the Unit Rates
To find the unit rates of these ratios, divide the first quantity (miles) by the second quantity (hours). This gives you a numerical value that represents the rate per one hour:
- a) 4 miles ‚à ö‚à ë 3 1/3 hours = 1.2
- b) 1/3 mile ‚à ö‚à ë 2 3/8 hours = approximately 0.14
- c) 9/8 miles ‚à ö‚à ë 5/6 hour = 1.35
- d) 9/5 miles ‚à ö‚à ë 3 hours = 1.8
- e) 2 1/2 miles ‚à ö‚à ë 3 hours = approximately 0.83
- f) 7 miles ‚à ö‚à ë 3/4 hour = 9.33
Step 3: Determine Ratios with Unit Rate Greater than 1
Finally, compare each calculated unit rate to determine which are greater than 1. The ratios meeting this criteria are:
- a) 4 miles : 3 1/3 hours
- c) 9/8 miles : 5/6 hour
- d) 9/5 miles : 3 hours
- e) 2 1/2 miles : 3 hours
- f) 7 miles : 3/4 hour
Hence, a), c), d), e), and f) have a unit rate greater than 1.