1) Highest air temperature = San Diego, CA

2) Highest dew point temperature = Miami, FL

Explanation- These two are clearly visible from the given data.

Now,

Saturation vapour pressure = 6.11 × e^((17.67×T)/(243.5+T))

Here, T= Temperature in Celsius

Temp in C = 5(Temp in F-32)/9

3) Highest saturation vapour pressure = San Diego, CA

Temp in Celsius = 5 ( 87-32)/9 = 30.55 degrees

Saturation vapour pressure = 43.81718

Now,

Vapour pressure = 6.11 × e^((17.67×Td)/(243.5+Td))

4) Highest vapour pressure = Miami, FL

Vapour pressure = 29.624

Now,

Td = T - (100 - RH)/5

=> RH = 100 - (5×(T - Td))

5) Highest relative humidity = Fargo, ND

Relative humidity(%) = 100 - (5×(5.55-3.33)) = 88.9

6) Lowest air temperature = Fargo, ND

7)Lowest dew point temperature= Fargo, ND

8) Lowest saturation vapour pressure = Fargo, ND

Saturation vapour pressure = 9.061

9) Lowest vapour pressure = Fargo, ND

Vapour pressure = 7.7566

10) Lowest relative humidity = San Diego, CA

Relative humidity(%) = 100 - 5×(30.55-10.55) = 0

All the temperatures were converted to Celcius during calculations.