Earlier in the text i found that i have a SD of 5.7626 for WMT, and using excel's STDEV.S function got the SD of 12.7650 for AMZN.

i used:

(.4)(5.7626)+(.6)(12.7650)=

(2.3050)+(5.8335)=

9.9640

but that was wrong? How do i do this by HAND?

by hand written i mean please do work the problem, show work, and upload a pdf or picture.

is there an equation im missing?

this is my work by hand to find the SD of WMT which was marked correct:

i found this equation on youtube, is this the missing equation and if so can you please solve using this?

Click here to open the spreadsheet - then open the "Data" worksheet. What is the standard deviation of a portfolio with 40% allocated to Walmart and 60% allocated to Amazon over the 5 months in 2020? Answer in \% terms w/o \% sign and to 4 decimal places (1.2345) 9.2078 (with margin: 0.0002 ) 0 (with margin: 0 ) 0 (with margin: 0 ) 0 (with margin: 0 ) Walmart Standard Deviation =50.7251225s=n1 Standard Deviation of a Two Stock Portfolio Standard Deviation of a 2-Security Portfolio p=wa2a2+wb2b2+2wawbabcorra,b