Question

a survey of two communities asked residents which candidate they supported for a local election. the survey data are shown in the relative frequency table.

	walker	olunloyo	total
mountain view	0.20	0.18	0.38
total	0.52	0.48	1.0

what percentage of the mountain view residents polled supported olunloyo?
a. 30%
b. 37.5%
c. about 47%
d. 18%

Explanation:

Step1: Identify relevant data

From the table, for Mountain View residents, the relative - frequency of those who supported Olunloyo is 0.18 and the total relative - frequency for Mountain View is 0.38.

Step2: Calculate the percentage

We use the formula for percentage within a subgroup: $\text{Percentage}=\frac{\text{Frequency of Olunloyo in Mountain View}}{\text{Total frequency of Mountain View}}\times100\%$. Substituting the values, we get $\frac{0.18}{0.38}\times100\%=\frac{18}{0.38}\% \approx 47.37\%$.

Answer:

C. About 47%