To determine the patient's weight in kilograms, we begin by noting that 1 kilogram equals 2.2 pounds. The patient weighs 170 pounds. Here’s the step-by-step process to convert the weight from pounds to kilograms and then round the result to the nearest tenth:
1. Convert pounds to kilograms:
[tex]\[
\text{Weight in kilograms} = \frac{\text{Weight in pounds}}{\text{Conversion factor}}
\][/tex]
With a weight of 170 pounds and a conversion factor of 2.2:
[tex]\[
\text{Weight in kilograms} = \frac{170}{2.2} \approx 77.27272727272727
\][/tex]
2. Round to the nearest tenth:
To round to the nearest tenth, we look at the digit in the hundredths place, which is 7 in this case. Since it is 5 or greater, we round the value up:
[tex]\[
\text{Weight in kilograms rounded to the nearest tenth} \approx 77.3
\][/tex]
Therefore, the patient's weight in kilograms, rounded to the nearest tenth, is 77.3 kg.
So the correct answer is:
D. 77.3 kg.
