Alteryx-Core Data Preparation Practice Question
You have a column containing values like '1,000.00' that you need to use in a calculation. If you attempt to use it directly in a Formula tool, it returns an error. What is the correct approach to clean this data for math?
⚠ Common exam trap
Candidates often try to use the Select tool to change the type directly to 'Double' or 'Int', which fails because Alteryx cannot automatically parse strings containing commas into valid numeric formats.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use a Formula tool to replace commas with an empty string and then convert to number.
The presence of thousands-separators (commas) prevents Alteryx from interpreting the string as a numeric value. To resolve this, you must first strip the commas using the ReplaceChar() function, then convert the remaining clean string into a number using the ToNumber() function. This sequence is a vital skill for handling financial data, which often includes formatting characters that are incompatible with raw numeric operations in Alteryx.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use the Data Cleansing tool to remove all punctuation.
Why it's wrong here
While the Data Cleansing tool can remove some characters, it lacks the specific granular control required to replace only commas while preserving the decimal point. Removing all punctuation would turn '1,000.00' into '100000', which significantly alters the numeric value, making the data unusable for accurate calculations.
- ✓
Use a Formula tool to replace commas with an empty string and then convert to number.
Why this is correct
Replacing the comma with an empty string produces '1000.00', which is a valid numeric string representation. The ToNumber() function can then successfully parse this string into a float or double, allowing for subsequent mathematical calculations to proceed without errors caused by non-numeric characters in the field.
- ✗
Use the Select tool to change the type to Double.
Why it's wrong here
The Select tool cannot automatically interpret or strip non-numeric characters like commas from a string during a type conversion. Attempting to change a string field containing '1,000.00' directly to Double will result in all values becoming null, as Alteryx cannot perform the implicit conversion of commas.
- ✗
Use the Text to Columns tool to split the number by the comma.
Why it's wrong here
Splitting by a comma would create two separate columns: '1' and '000.00'. This separates the components of the number, making it impossible to treat the original value as a single numeric entity. Recombining these parts would be an unnecessarily complex process compared to string replacement.
Visual reference
About these practice questions
One of 142 original Alteryx-Core practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Alteryx exam blueprint
This Alteryx-Core practice question is part of Courseiva's free Alteryx certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the Alteryx-Core exam.