Home / 708.63-978-398.13

Finding the Fourth Proportional to 708.63, 978 and 398.13

Calculator

Solution

The fourth proportional to 708.63, 978 and 398.13 is: 549.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.63 : 978 = 398.13 : x
  2. Step 2: Convert to fraction form
    708.63/978 = 398.13/x
  3. Step 3: Cross multiply
    708.63x = 978 × 398.13
  4. Step 4: Simplify right side
    708.63x = 389,371.14
  5. Step 5: Solve for x
    x = 389,371.14/708.63
  6. Step 6: Final answer
    x = 549.47

Related Problems

Find fourth proportional to 354.32, 489 and 199.07
Half scale
Find fourth proportional to 1,417.26, 1,956 and 796.26
Double scale
Find fourth proportional to 709.63, 979.38 and 399.13
Similar ratio
Find fourth proportional to 1,062.95, 1,467 and 597.20
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.