Study the following graph carefully and answer the questions that follow :

| Aspect | Stage I (High Fluctuating) | Stage III (Low Fluctuating) |
|---|---|---|
| Characteristics | High birth rates and high death rates, resulting in low population growth. | Low birth rates and low death rates, resulting in very low population growth or decline. |
| Causes | Poor healthcare, high infant mortality, limited food/resources, frequent epidemics. | Advanced healthcare, contraception use, higher education, economic development. |
| Examples | Rainforest tribes, remote communities. | Developed countries like Canada, Japan, USA. |
| Birth Rate | High | Low |
| Death Rate | High | Low |
| Population Growth | Low | Very low or stable |
| Socio-economic Conditions | Primitive or underdeveloped | Highly developed |

A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:
(iii) (b) If the foot of the ladder, whose length is 5 m, is being pulled towards the wall such that the rate of decrease of distance \( y \) is \( 2 \, \text{m/s} \), then at what rate is the height on the wall \( x \) increasing when the foot of the ladder is 3 m away from the wall?