So, the stock value at the end of December was $349.52
1.) From the table, the change in price in January was a positive $33.88.
Simply add $33.88 to $349.52 (which equals to $383.40)
2.) From the table, the change in price in February was a negative $48.59.
Simply subtract $48.59 from the total (which equals to $334.84)
3.) From the table, the change in price in March was a positive $12.77.
Simply add $12.77 to the previous total (which now equals to $347.58)