The following three defense stocks are to be combined into a stock index in January $2016($perhaps a portfolio manager believes these stocks are an appropriate benchmark for his or her performance$)$: Suppose that Douglas McDonnell shareholders approve a $2-$for$-1$ stock split on January $1,2017.$

Price

Shares

$($millions$)1/1/161/1/171/1/18$

Douglas McDonnell $215$ $ $64$ $ $68$ $ $82$

Dynamics General $455726478$

International Rockwell $25010190106$

What is the new divisor for the index? $($Do not round intermediate calculations. Round your answer to $3$ decimal places.$)$

b$.$ Calculate the rate of return on the index for the year ending December $31,2017,$ if Douglas McDonnell$$s share price on January $1,2018,$ is $$24\mathrm{.}73$ per share. $($Do not round intermediate calculations. Enter your answer as a percent rounded to $2$ decimal places.$)$