Question

A survey for a certain year found that 90% of pregnant women received medical care at least once before giving birth. Of these women, 60% received medical care from doctors, while 40% received medical care from other healthcare providers. Given this information, which one of the following statements can be inferred with certainty?

• A. More than half of the pregnant women received medical care at least once from a doctor.
• B. Less than half of the pregnant women received medical care at least once from a doctor.
• C. More than half of the pregnant women received medical care at most once from a doctor.
• D. Less than half of the pregnant women received medical care at most once from a doctor.

Hint:

When solving percentage-based survey problems, always assume a total of $100$ for simplicity. This allows quick conversion of percentages into actual numbers and makes inference checking easier.

Answer 1

The Correct Option is A

Step 1: Identify the base group.
90% of pregnant women received medical care at least once before giving birth. Assume a total of $100$ pregnant women. Thus, $90$ women received medical care.
Step 2: Split into doctor vs other healthcare providers.
Out of these $90$ women: \[ 60% \text{ received care from doctors } = 0.6 \times 90 = 54 \] \[ 40% \text{ received care from other providers } = 0.4 \times 90 = 36 \] Step 3: Interpretation.
This means at least $54$ out of $100$ pregnant women (i.e., 54%) received medical care from doctors. Since $54%>50%$, this shows that more than half of the total pregnant women received medical care from doctors.
Step 4: Certainty of inference.
The only inference that can be made with certainty is option (A). The other statements (less than half or at most once) cannot be concluded from the given information. \[ \boxed{\text{More than half of the pregnant women received medical care at least once from a doctor.}} \]