Question

1. a laboratory technician counts 7,540 leukocytes in a sample. if 40 % of the leukocytes are neutrophils, how many neutrophils are present?
2. marissa is weighed as part of her physical examination. she weighs 136 pounds. how many kilograms does she weigh?
3. her brother, marcus, is also weighed. he weighs 174 pounds. how many kilograms does he weigh?
4. marissa is measured and she is 55\ tall. how many inches tall is she?
5. if marissa is 55\ inches tall, how many centimeters tall is she?
6. marcus is also measured and he is 59\ tall. how many inches tall is he?
7. if marcus is 59\ tall, how many centimeters tall is he?
8. the nurse needs to administer 125 mg of a medication that is available in the following strength: 250 mg/5 ml. how many ml will the nurse need to administer?

Explanation:

Step1: Calculate number of neutrophils

Multiply total leukocytes by percentage.
$7540\times0.4 = 3016$

Step2: Convert Marissa's weight to kg

Use conversion factor 1 lb = 0.453592 kg.
$136\times0.453592\approx61.69$

Step3: Convert Marcus's weight to kg

Use conversion factor 1 lb = 0.453592 kg.
$174\times0.453592\approx78.93$

Step4: Convert Marissa's height to inches

1 foot = 12 inches, so $5\times12 + 5=65$ inches

Step5: Convert Marissa's height to cm

1 inch = 2.54 cm, so $65\times2.54 = 165.1$ cm

Step6: Convert Marcus's height to inches

1 foot = 12 inches, so $5\times12+9 = 69$ inches

Step7: Convert Marcus's height to cm

1 inch = 2.54 cm, so $69\times2.54 = 175.26$ cm

Step8: Calculate volume of medication

Set up proportion $\frac{250}{5}=\frac{125}{x}$, cross - multiply: $250x=125\times5$, then $x=\frac{125\times5}{250}= 2.5$ mL

Answer:

1. 3016
2. 61.69 kg
3. 78.93 kg
4. 65 inches
5. 165.1 cm
6. 69 inches
7. 175.26 cm
8. 2.5 mL