The PROB function returns the probability that values in a range are between two limits. If upper_limit is not supplied, returns the probability that values in x_range are equal to lower_limit.
Syntax:= PROB(x_range, prob_range, [lower_limit], [upper_limit])
The PROB function syntax has the following arguments:
 X_range (required argument) – This is the range of numeric values of x with which there are associated probabilities.
 Prob_range (required argument) – This is the set (array) of probabilities that is associated with values in x_range. The array must be of the same length as the x_range array and the values in prob_range must add up to 1.
 Lower_limit (optional argument) – This is the lower boundary of the value for which we want a probability.
 Upper_limit (optional argument) – This is upper boundary of the value for which you want a probability. When we omit this argument, the PROB function will simply return the probability associated with the value of the supplied lower_limit.
Example: Let’s look at some Excel PROB function examples and explore how to use the PROB function as a worksheet function in Microsoft Excel:
Suppose we are given the data below:
Syntax: =PROB(A2:A11,B2:B11,A2)
Result: 0.3
Based on the Excel spreadsheet above, the following PROB examples would return:
Syntax: =PROB(A2:A11,B2:B11,700)
Result: 0.25
Syntax: =PROB(A2:A11,B2:B11,C4,D4)
Result: 0.35
Syntax: =PROB(A2:A11,B2:B11,C5,D5)
Result: 0.5
Syntax: =PROB(A2:A11,B2:B11,C6,D6)
Result: 0.75
Syntax: =PROB(A2:A11,B2:B11,C7,D7)
Result: 0.22
Syntax: =PROB(A2:A11,B2:B11,1100,1400)
Result:0.2
Note:
 If any value in prob_range ≤ 0 or if any value in prob_range > 1, PROB returns the #NUM! error value.
 If the sum of the values in prob_range is not equal to 1, PROB returns the #NUM! error value.
 If upper_limit is omitted, PROB returns the probability of being equal to lower_limit.

If x_range and prob_range contain a different number of data points, PROB returns the #N/A error value.