Answer to Question #218323 in Statistics and Probability for yotori

Question

The following table shows the ‘less than’ cumulative frequency distribution of the waiting times at college bus stops for a random sample of 120 students.

 

Waiting times (in minutes) Number of students

<10 18

<20 54

<30 84

<50 102

<70 120

 

a)

(i) State the variable of interest.

(ii) Indicate whether the variable of interest in Question 1 a) (i) is qualitative, quantitative

continuous, or quantitative discrete.

(iii) Variables was collected from population or sample?

 

b) Construct a percentage cumulative frequency distribution. Then, draw a ‘less than’

percentage cumulative frequency ogive.

 

c) Use the graph obtained in Question 1 (b), estimate

(i) the median, and interpret the result.

(ii) the percentage of students who have waiting times of more than 40 minutes.

 

d) Redraft the cumulative frequency distribution into a grouped frequency distribution.

 

e) Calculate the mean, variance and standard deviation.