Economics - Reading 14 Example 15

Can someone pls provide a detailed explanation on how they got the alpha value as input for the growth accounting equation?

Alpha is the capital share of output. The model assumes 2 factors of production and an exogenous multiplier A (technology). Capital and labor shares sums 100% or 1.0. So alpha + labor share in output = 1.

You are given the labor share in output for each year. Calculate the average and you will get 61.7%, so alpha is 38.3%.

Hope this helps.