To solve the problem, we need to use proportional reasoning to find out how much it would cost to buy 2.6 pounds of steak, given that 4 pounds cost $45.80.

Steps:

1. Find the cost per pound of steak: Since 4 pounds of steak cost $45.80, the cost per pound is: $\text{Cost per pound} = \frac{45.80}{4} = 11.45 \, (\text{dollars per pound})$

2. Multiply by the number of pounds (2.6): Now that we know the cost per pound, multiply it by 2.6 pounds to find the total cost: $\text{Cost for 2.6 pounds} = 11.45 \times 2.6 = 29.77$

So, the cost to buy 2.6 pounds of steak is $29.77.

Would you like further explanation or have any other questions?

Here are five related questions for practice:

1. How much would 3 pounds of steak cost if 4 pounds cost $45.80?
2. If 5 pounds of steak cost $57.25, how much would 2.5 pounds cost?
3. If the price per pound increases to $12, how much would 2.6 pounds cost?
4. How much would 10 pounds of steak cost at the same price per pound?
5. If you only have $30, how many pounds of steak could you buy?

Tip: When dealing with proportional problems, always start by calculating the unit price.