0.25 x 15% + 0.25 x 12% + 0.25 x 10% + 0.25 x 8% = 11.25%.

The difference caused by the differences in recognition of warranty expense is the only item that is a timing difference. The others are all permanent differences.

The NAV and the market price of a closed-end fund do not usually correspond. Traditionally, the market price of these shares has been between 5 to 20% below the NAV (i.e. closed-end funds generally sell at a discount to NAV). A closed-end investment fund does not offer new shares and does not repurchase outstanding shares on demand (i.e. the amount of money invested is relatively fixed).
Consequently, a closed-end fund trades much like a typical stock and may sell for a price above or below the NAV (net asset value). The market price of the investment company shares is determined by the relative supply and demand for the investment company stock in the public secondary market.

Since accounts receivables increased, cash sales were less than shown, i.e., Cash sales =
Accrual sales - Increase in A/C Rec. = 23,085 - 2,317 = 20,768
According to the accounting entity, COGS = Opening Inventory + Purchases - Closing Inventory,
Purchases = COGS + Change in Inventory. Thus, Cash COGS = 12,697 - 894 = 11,803