Which of the following statements about the Indifference Curve Approach are correct?

1. Indifference curves are convex to the origin due to diminishing marginal rates of substitution.
2. Higher indifference curves represent higher levels of satisfaction.
3. Indifference curves can intersect if the consumer's preferences change.
4. The slope of the indifference curve represents the marginal rate of substitution (MRS).
5. Consumer equilibrium is achieved when the indifference curve is tangent to the budget line.