Employee and Non-employee Director Stock Option and Retirement Plans (Tables)

6 Months Ended

Feb. 29, 2020

Compensation Related Costs [Abstract]

Schedule of assumptions about stock options

The estimated fair value of employee stock options granted on November 1, 2019 was determined with the following assumptions:

November 1, 2019 Grant Details
Risk-free interest rate	1.59% - 1.79%
Expected life (years)	7.22
Expected volatility	23% - 26%
Dividend yield	1.09%
Estimated fair value	$60.19
Exercise price	$255.87
Fair value as a percentage of exercise price	23.5%

using the Black-Scholes option-pricing model with the following assumptions:

January 15, 2020 Grant Details
Risk-free interest rate	1.64%
Expected life (years)	5.4
Expected volatility	22.0%
Dividend yield	1.11%
Estimated Fair Value	$54.74
Exercise price	$271.51
Fair value as a percentage of exercise price	20.2%