The Price Index is a statistical measure that shows changes in the value of a representative bundle of goods and services over time. For a base year of 1960 and a current price index of 330, it would imply that the average price level of certain goods and services has increased by 3.3 times since 1960.

Option 1 suggests all items are costing 3.3 times more, which is too broad as the price index is based on a select basket of goods, not all.

Option 2 implies that only prices of certain selected items have increased 3.3 times. This is also incorrect because price index measures the change in the average level of prices, not individual prices.

Option 4 singles out gold prices, which is incorrect. A price index usually includes a diverse basket of goods and services, not just one commodity.

On the other hand, option 3 includes the key term "weighted mean of prices," which describes how price indices are calculated. Therefore, the correct answer is "the weighted mean of prices of certain items has increased 3.3 times."