# Practice Problems & Solutions

Have a go at these practice problems in Causal, which cover a range of different concepts - e.g. cohorts, scenarios, seasonality, views etc. All of it can be learnt by navigating our docs
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Model 1: Growth rates, categories, seasonality, scenarios, visuals
• a company has 100 users on Jan 1 2022 and wants to model out the business for the next 2 years on a monthly basis
• 80% are on the pro plan and the rest on the business plan
• they expect a 10% MoM growth rate for the business plan and a 15% growth rate for the pro plan
• every December, there’s an additional 10% growth due to Xmas
• create a stacked bar chart to display the user growth over time
• add a scenario “No seasonality” in which you remove the Xmas growth
• compare the total user numbers of the two scenarios in a line chart
• create a Freeform visual that displays the difference between the two outcomes
Model 2: Cohorts, scenarios
• First learn about cohort modeling in Causal
• a company gets 100 new users each month
• create a 3 year monthly Causal model
• after the first month 30% cancel, in the next month 10% cancel, next month another 10%, after that every month 1% cancel
• create a cohort model showing the size of each cohort over time
• each user pays \$10/month — calculate the total revenue over time
• create a scenario called “trial period” in which new users don’t pay for the first month
• compare the two scenarios on a chart
• compare them on a table
Model 3: Multiple linked categories, tables
• create the following categories:
• country: UK, US, Singapore, Germany, Switzerland
• region: US, Europe, Asia
• team: Engineering, Sales
• map countries to regions
• create an “Initial Employees” variable explicitly broken down by country and team and add some dummy numbers
• create a growth rate variable split by region (20% in Asia and 10% outside of Asia)
• create a "Running headcount" variable that takes the Initial Employees in month 1 of the model, then grows by the growth rate for future months
• create a table and show the employees by country and team
• create a variable that groups the employees by region and team, and a table that shows this
• create a “salary per employee” variable: 100 for sales, 100 for eng
• compute the total salary over time
• apply a 10% bonus in US and a 5% bonus outside of US
Model 4: Data, categories, versions (forecast vs. actuals)
• clone model 3
• create a google sheet and load the first 4 months of employee counts from a google sheet
• create a version called “Month 4”