Loading...
A financial adviser was showing a client the value, rounded to the nearest cent, of an initial investment of \(\$100.00\) after 5, 10, 15, 20, 25, and 30 years, under the assumption that the value increases by \(\mathrm{r}\%\) per year for some positive constant r. The adviser correctly gave \(\$130.01\) for the value after 5 years. However, the adviser inadvertently made two transcription errors, and as a result, two of the remaining values shown to the client were incorrect.
Assuming the options provided are the remaining five amounts shown to the client, select for First error the lesser of the two incorrectly transcribed values and select for Second error the greater of the two incorrectly transcribed values. Make only two selections, one in each column.
First error
Second error
$160.02
$219.75
$285.70
$317.43
$482.90
Let's create a timeline showing the investment growth:
$100 → $130.01 → ? → ? → ? → ? → ?
Year 0 Year 5 Year 10 Year 15 Year 20 Year 25 Year 30
Since the investment grows at a constant rate r% per year:
Using calculator: 1.3001(1/5) ≈ 1.0539
So the annual growth rate is approximately 5.39%
We need to:
Using the compound interest formula with (1 + r)5 = 1.3001:
Year 10: $100 × (1 + r)10 = $100 × (1.3001)2 = $100 × 1.69026 ≈ $169.03
Year 15: $100 × (1 + r)15 = $100 × (1.3001)3 = $100 × 2.19764 ≈ $219.76
Year 20: $100 × (1 + r)20 = $100 × (1.3001)4 = $100 × 2.85672 ≈ $285.67
Year 25: $100 × (1 + r)25 = $100 × (1.3001)5 = $100 × 3.71288 ≈ $371.29
Year 30: $100 × (1 + r)30 = $100 × (1.3001)6 = $100 × 4.82697 ≈ $482.70
Let's match our calculated values with the answer choices:
| Year | Calculated | Given Choice | Status |
| 10 | $169.03 | $160.02 | × ERROR (too low) |
| 15 | $219.76 | $219.75 | ✓ Correct (within rounding) |
| 20 | $285.67 | $285.70 | ✓ Correct (within rounding) |
| 25 | $371.29 | $317.43 | × ERROR (too low) |
| 30 | $482.70 | $482.90 | ✓ Correct (within rounding) |
The two transcription errors are:
Since we need to select the lesser error as "First error" and the greater error as "Second error":
First error (lesser value): $160.02
Second error (greater value): $317.43