How to Compute Sex Ratios:

Males: 100 females

• From raw data: 1063 bulls, 2784 cows

1063 / 2784 = x / 100

x = (1063 / 2784) x 100 = 38.2

Therefore, 38:100 is the conventional sex ratio.

• From female percentage: 60% females

60 /100 = 100 / (x + 100)

x = 66

Therefore, 66:100 is the conventional sex ratio.

• From male percentage: 60% males

(100 -60) / 100 = 100 / (x + 100)

x = 150

Therefore, 150:100 is the conventional sex ratio.

Percentages

• Percent females from raw data: 1063 bulls, 2784 cows.

2784 / (1063 + 2784) = 0.724

Therefore, the percentage is 72% females.

• Percent males from raw data: 1063 bulls, 2784 cows.

1063 / (1063 + 2784) = 0.276

Therefore, the percentage is 28% males.

• Percent females from sex ratio: 60:100

100 / (60 + 100) = 0.625

Therefore, the percentage is 63% females.

Return to Lecture Notes VI: Population Structure.

Updated 05 August 1996