Question

170 people are asked how many siblings they have? the (incomplete) results are shown below (please use 4 decimal places when apply): # of siblings frequency relative frequency cumulative frequency 0 32 0.1882 32 1 0.2294 71 2 37 0.2176 108 3 29 137 4 33 0.1941 complete the table and determine what percent of the people have exactly zero sibling(s)?

Explanation:

Step1: Find frequency of 1 sibling

We know that cumulative frequency of 1 sibling is 71 and cumulative frequency of 0 sibling is 32. So the frequency of 1 sibling is $71 - 32=39$.

Step2: Find relative frequency of 3 siblings

Relative frequency = $\frac{\text{Frequency}}{\text{Total number of people}}$. Total number of people is 170. Frequency of 3 siblings is 29. So relative frequency of 3 siblings is $\frac{29}{170}\approx0.1706$.

Step3: Find cumulative frequency of 4 siblings

Cumulative frequency of 4 siblings is the sum of all frequencies up to 4 siblings. Since cumulative frequency of 3 siblings is 137 and frequency of 4 siblings is 33, the cumulative frequency of 4 siblings is $137 + 33 = 170$.

Step4: Find percentage of people with 0 siblings

Relative frequency of people with 0 siblings is 0.1882. To convert to percentage, we multiply by 100. So the percentage is $0.1882\times100 = 18.82\%$.

Answer:

# of Siblings	Frequency	Relative Frequency	Cumulative Frequency
1	39	0.2294	71
2	37	0.2176	108
3	29	0.1706	137
4	33	0.1941	170

The percentage of people with exactly 0 siblings is 18.82%