Home / 975.59-1,345.30-643.59

Finding the Fourth Proportional to 975.59, 1,345.30 and 643.59

Calculator

Solution

The fourth proportional to 975.59, 1,345.30 and 643.59 is: 887.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    975.59 : 1,345.30 = 643.59 : x
  2. Step 2: Convert to fraction form
    975.59/1,345.30 = 643.59/x
  3. Step 3: Cross multiply
    975.59x = 1,345.30 × 643.59
  4. Step 4: Simplify right side
    975.59x = 865,821.63
  5. Step 5: Solve for x
    x = 865,821.63/975.59
  6. Step 6: Final answer
    x = 887.49

Related Problems

Find fourth proportional to 487.80, 672.65 and 321.80
Half scale
Find fourth proportional to 1,951.18, 2,690.60 and 1,287.18
Double scale
Find fourth proportional to 976.59, 1,346.68 and 644.59
Similar ratio
Find fourth proportional to 1,463.39, 2,017.95 and 965.39
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.