Home / 452.20-678.30-257.80

Finding the Fourth Proportional to 452.20, 678.30 and 257.80

Calculator

Solution

The fourth proportional to 452.20, 678.30 and 257.80 is: 386.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    452.20 : 678.30 = 257.80 : x
  2. Step 2: Convert to fraction form
    452.20/678.30 = 257.80/x
  3. Step 3: Cross multiply
    452.20x = 678.30 × 257.80
  4. Step 4: Simplify right side
    452.20x = 174,865.74
  5. Step 5: Solve for x
    x = 174,865.74/452.20
  6. Step 6: Final answer
    x = 386.70

Related Problems

Find fourth proportional to 226.10, 339.15 and 128.90
Half scale
Find fourth proportional to 904.40, 1,356.60 and 515.60
Double scale
Find fourth proportional to 453.20, 679.80 and 258.80
Similar ratio
Find fourth proportional to 678.30, 1,017.45 and 386.70
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.