Final answer:
Stock market investments like stocks and mutual funds offer high potential returns without a fixed amount due to their rate of return fluctuations, being suitable for young investors with a long-term outlook.
Step-by-step explanation:
The type of investment that has a high potential return but does not promise a specific amount is typically found in the stock market. These investments are known for having a high average return over several years or decades. However, they also come with a high risk due to the fact that in the short term, ranging from months to a few years, the rate of return can fluctuate significantly. Investments such as mutual funds and stocks fall into this category, as they carry the potential for higher returns compared to low-risk options like bank accounts and bonds but do not guarantee a fixed return amount. Young investors, in particular, are often encouraged to invest in these higher-risk assets, as they have time to weather the volatility and benefit from the long-term growth potential.