JUBAIL UNIVERSITY COLLEGE SEMESTER 422 MATH 117 – Homework1 Question 1: Data were collected on the number of people entering an electronic store each hour

JUBAIL UNIVERSITY COLLEGE

SEMESTER 422

MATH 117 – Homework1

Question 1:

Data were collected on the number of people entering an electronic store each hour. The discrete data are presented below.

     14,    18,     22,     24,     25,     25,     28,     28,     29,     29

     35,     37,     37,     39,     43,     43,     47,     49,     50,     53

1. Construct a stem – leaf diagram.

2. Starting with a class interval of 14 to 21 as the first class, construct a frequency distribution, cumulative frequency, relative frequency, cumulative relative frequency of the data.   

Question 2:

For the sample data below:

88, 71, 74, 85, 77, 100, 71, 95, 98, 99

 Find the following:

1. Mean
2. Mode
3. Median
4. Variance
5. Standard deviation

 Question 3:

a) A candidate obtained the following percentages of marks: English 70%, Mathematics 90%, Statistics 75%, Chemistry 88%, and Physics 79%, and the weights of 3, 1, 3, 2, 2.

1. Find the weighted average.

2. Find the unweighted average.    

 b) The registrar of a University has been asked to prepare a report about the graduate students. Among other things, he wants to analyze the ages of students. He has taken a sample of 10 graduate students and has found the following ages:

36,   22,   24,   27,   27,   33,   28,   23,   24,   21      

1. Compute the Interquartile range.

2. Find the 86^th percentile.
3. Develop a box and whisker plot. 

 Question 3:

1. 1. If the laboratory technician Hussam has an average of 50 completed work per day with standard deviation of 5 and technician Sameer has an average of 120 with a standard deviation of 15 completed works per day. Find which technician has less variability. 

 b) Assume that Jubail University College accepts students with largest IQ as an indication of intelligence. If the SAT scores has mean of 1600, with a standard deviation of 200, the TRADITIONAL test scores has mean of 80 and standard deviation of 10 and they are all bell-shaped. Jennifer had a score of 2040 on the SAT test and Lucy had a score of 120 on the TRADITIONAL test. From the test scores, who is more intelligent Jennifer or Lucy?