Question

160 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 29 1 36 0.225 65 2 0.2 97 3 38 0.2375 135 4 25 0.1563 160 complete the table and determine what percent of the people have exactly three sibling(s)?

Explanation:

Step1: Calculate relative frequency for 0 siblings

Relative frequency = $\frac{\text{Frequency}}{\text{Total number of people}}$. Total number of people is 160. For 0 siblings, frequency is 29. So relative frequency = $\frac{29}{160}= 0.18125\approx0.1813$.

Step2: Calculate cumulative frequency for 0 siblings

Cumulative frequency for 0 siblings is just the frequency of 0 siblings, which is 29.

Step3: Calculate frequency for 2 siblings

Since relative - frequency for 2 siblings is 0.2 and total number of people is 160, frequency = $0.2\times160 = 32$.

Step4: Calculate percentage of people with 3 siblings

Relative frequency of people with 3 siblings is 0.2375. To convert to percentage, multiply by 100. So percentage = $0.2375\times100 = 23.75\%$.

Answer:

# of Siblings	Frequency	Relative Frequency	Cumulative Frequency
1	36	0.2250	65
2	32	0.2000	97
3	38	0.2375	135
4	25	0.1563	160

The percent of people with exactly three siblings is 23.75%