Instructions

Please read the Jupyter Notebook of Session 1 and finish the questions below.  Submit a Jupyter Notebook of your solutions with code on Blackboard.  The total achievable points are 6 for this problem set. Please name your Jupyter Notebook as

• YourLastName_YourFirstName_PS1.ipynb (e.g., Zhang_Renyu_PS1.ipynb)

1.  Playing with the WHO Data Set (3 points)

Please read the data set WHO.csv into Python and answer the following questions:

(a)  (0.6 point) Missing data. Which variables have at least THREE missing (i.e., NA) value? (b)  (0.6 point) Fertility rate. Which country has the highest and lowest fertility rate?

(c)  (0.6 point) Variations  of  GNI. Which region has the minimum variation (measured by standard deviation) in Gross National Income (GNI)? What is the standard deviation of GNI in this region?

(d)  (0.6 point) Child mortality of rich countries. We define a country to be a rich country if its GNI exceeds $20,000. What is the mean child mortality of the rich countries?

(e)  (0.6 point) Correlation.  Demonstrate the relationship between income level vs.  life ex- pectancy through calculating their correlations and visualization.

2.  User Retention (3 points)

The data set Retention.csv contains the active user information of an App for 3 days.  It has three variables:

• user_id: A unique identifier for each user.

• play_duration: The amount of time (in minutes) the user uses the App.

• day: The day of the record.

Note that only users who are active (i.e., log into the App) will be recorded in this data set. Please load the data set into Python and answer the following questions. Hint: You need to use the join operator to link the active users of different days together.