Home / 708.40-977.60-397.88

Finding the Fourth Proportional to 708.40, 977.60 and 397.88

Calculator

Solution

The fourth proportional to 708.40, 977.60 and 397.88 is: 549.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.40 : 977.60 = 397.88 : x
  2. Step 2: Convert to fraction form
    708.40/977.60 = 397.88/x
  3. Step 3: Cross multiply
    708.40x = 977.60 × 397.88
  4. Step 4: Simplify right side
    708.40x = 388,967.49
  5. Step 5: Solve for x
    x = 388,967.49/708.40
  6. Step 6: Final answer
    x = 549.08

Related Problems

Find fourth proportional to 354.20, 488.80 and 198.94
Half scale
Find fourth proportional to 1,416.80, 1,955.20 and 795.76
Double scale
Find fourth proportional to 709.40, 978.98 and 398.88
Similar ratio
Find fourth proportional to 1,062.60, 1,466.40 and 596.82
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.