Statistics and Probability Answers

Identify whether the  following variables would be measured in Nominal, Ordinal, Interval  or Ratio Scale.

a.  Number  of logins to Facebook per day. _____________

b.  Social class ___________________

c.  Performance Scale____________________

d.  Military ranks ____________________

e. Hair color    ____________________

f.  Religion ___________________

g.  Gender ____________________

h.  Meal Preference _____________________

i.  Social Sites ____________________

j.  Number of children in families  ____________________

A computer manager needs to know how efficiency of her new computer program depends on the size of incoming data. Efficiency will be measured by the number of processed requests per hour. Applying the program to data sets of different sizes, she gets the following results:-

Data Size (gigabytes) (x)

6    7   7   8  10 10 15

Processed requests(y)

40 55 50 41 17 26 16

a.      Find the equation of regression line

b.     Interpret regression co-efficient and y intercept

c.      Can we take Data Size as dependent variable if yes then how? If not then why? Explain.

Could this problem be studied using correlation if yes then how? If not then why? Explain

  A manufacturer of a new light bulb would like to demonstrate that his product works twice as fast as the competitor’s product. The manufacturer would like to test

           H₀ :

           H₁ :

Where are the mean life time of the bulbs of manufacture’s product and competitor’s product, respectively? Assume that both population variances are known. Develop a procedure for testing the above hypothesis.

A rowing team consists of four rowers who weigh 18, 24,and 36 pounds. Find all possible random samples with replacement of size three and compute the sample mean for each one. Use them to find the sampling distribution of the sample mean. Also verify the results.