Home / 840-1,260.42-455.25

Finding the Fourth Proportional to 840, 1,260.42 and 455.25

Calculator

Solution

The fourth proportional to 840, 1,260.42 and 455.25 is: 683.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    840 : 1,260.42 = 455.25 : x
  2. Step 2: Convert to fraction form
    840/1,260.42 = 455.25/x
  3. Step 3: Cross multiply
    840x = 1,260.42 × 455.25
  4. Step 4: Simplify right side
    840x = 573,806.21
  5. Step 5: Solve for x
    x = 573,806.21/840
  6. Step 6: Final answer
    x = 683.10

Related Problems

Find fourth proportional to 420, 630.21 and 227.63
Half scale
Find fourth proportional to 1,680, 2,520.84 and 910.50
Double scale
Find fourth proportional to 841, 1,261.92 and 456.25
Similar ratio
Find fourth proportional to 1,260, 1,890.63 and 682.88
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.