Home / 845.20-1,268.10-815.20

Finding the Fourth Proportional to 845.20, 1,268.10 and 815.20

Calculator

Solution

The fourth proportional to 845.20, 1,268.10 and 815.20 is: 1,223.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    845.20 : 1,268.10 = 815.20 : x
  2. Step 2: Convert to fraction form
    845.20/1,268.10 = 815.20/x
  3. Step 3: Cross multiply
    845.20x = 1,268.10 × 815.20
  4. Step 4: Simplify right side
    845.20x = 1,033,755.12
  5. Step 5: Solve for x
    x = 1,033,755.12/845.20
  6. Step 6: Final answer
    x = 1,223.09

Related Problems

Find fourth proportional to 422.60, 634.05 and 407.60
Half scale
Find fourth proportional to 1,690.40, 2,536.20 and 1,630.40
Double scale
Find fourth proportional to 846.20, 1,269.60 and 816.20
Similar ratio
Find fourth proportional to 1,267.80, 1,902.15 and 1,222.80
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.