Which of the following is the best estimate for 1.5^1.9?

A.175
B.204
C.36
D.67.5

1 answer

To estimate \( 1.5^{1.9} \), we can use the fact that \( 1.5^2 = 2.25 \) and \( 1.5^1 = 1.5 \).

Since \( 1.9 \) is closer to \( 2 \) than it is to \( 1 \), we can approximate:

\[ 1.5^{1.9} \approx \sqrt{1.5^2} = \sqrt{2.25} \approx 1.5 \]

However, to get a better estimate, we can interpolate between \( 1.5^1 \) and \( 1.5^2 \):

1.5 raised to \( 1.5 \) can be estimated by taking the geometric mean:

\[ 1.5^{1.5} \approx \sqrt{1.5 \times 2.25} = \sqrt{3.375} \approx 1.84 \]

Since \( 1.9 \) is between \( 1.5 \) and \( 2 \), \( 1.5^{1.9} \) will be slightly less than \( 2.25 \) but more than \( 1.84 \).

To get a rough estimate, we can calculate values for \( 1.5^{1.8} \) as well and find the right range.

Calculating \( 1.5^2 = 2.25 \), we find that:

Now we can compare the options given to see which value is closest to 1.5^1.9:

  • \( A. 175 \)
  • \( B. 204 \)
  • \( C. 36 \)
  • \( D. 67.5 \)

Since \( 1.5^{1.9} \approx 2.25 \), the closest estimate from the choices given is:

None of them seem to fit exactly, but if we think in terms of scale, values might be wrongly adjusted for presentation.

To clarify better estimates:

  • Roughly \( 1.5^{1.9} \) could approximate slightly below \( 2.25 \), signifying none of the provided options correctly represent the outcome.

Upon reviewing the estimates again considering practical rounding and real-world influences on mentioned approximation for scale:

Your best estimate, however arbitrary due to choice discrepancy, might still lean closest towards \( A. 175 \) despite inherent disparities since other values arrive way farther apart.

Thus the most rational estimate comparison would be \( D. 67.5 \) although the closest rational approach didn't fit pre-defined estimates.

Conclude: D. 67.5 is closer yet emphasizes arbitrary fitting towards expectations missed within calculated findings.