Microsoft : AI-900 中文 Questions & Answers

Correct Answer:

Explanation:

According to the Microsoft Azure AI Fundamentals (AI-900) and Azure Machine Learning documentation, regression is the appropriate machine learning task when the goal is to predict continuous numeric values- such as prices, sales amounts, or other measurable quantities.
In this scenario, the dataset contains motor vehicle sales data, and the objective is to predict vehicle sale values. A vehicle's sale value (price) is a continuous numeric variable, meaning it can take on a wide range of possible numbers (for example, $15,000, $28,500, $42,300). Regression models are designed to analyze relationships between input features (like make, model, mileage, age, fuel type) and a continuous output variable (price).
Automated Machine Learning (AutoML) in Azure simplifies this process by automatically testing multiple regression algorithms (e.g., Linear Regression, Random Forest, Gradient Boosted Trees) and hyperparameters to find the best-performing model.
Let's evaluate why the other options are incorrect:
* Classification - Used for predicting discrete categories (e.g., car type: sedan, SUV, or truck). Sale value prediction is not categorical.
* Time series forecasting - Used when predicting future values based on time-dependent data (e.g., sales over months or years). The question focuses on predicting price based on vehicle characteristics, not over time.
* Natural Language Processing (NLP) - Deals with text-based data, not numeric vehicle data.
* Computer Vision - Applies to image-based tasks (e.g., detecting car types from photos).
Therefore, per Microsoft Learn's Automated ML task selection guidance, when predicting a numeric output like vehicle sale value, the correct machine learning task type is Regression.
# Final answer: Regression

Correct Answer:

Explanation:

According to the Microsoft Azure AI Fundamentals (AI-900) official study guide and Microsoft Learn modules on machine learning concepts, ensuring that the accuracy of a predictive model can be proven requires data partitioning-specifically splitting the available data into training and testing datasets. This is a foundational concept in supervised machine learning.
When you split the data, typically about 70-80% of the dataset is used for training the model, while the remaining 20-30% is used for testing (or validation). The reason behind this approach is to ensure that the model's performance metrics-such as accuracy, precision, recall, and F1-score-are evaluated on data the model has never seen before. This prevents overfitting and allows you to demonstrate that the model generalizes well to new, unseen data.
In the AI-900 Microsoft Learn content under "Describe the machine learning process", it is explained that after cleaning and transforming the data, the next essential step is data splitting to "evaluate model performance objectively." By keeping training and testing data separate, you can prove the reliability and accuracy of the model's predictions, which is particularly crucial in sensitive domains like clinical or healthcare analytics, where decision transparency and validation are vital.
* Option A (Train the model by using the clinical data) is incorrect because you should not train and evaluate on the same data-it would lead to biased results.
* Option C (Train the model using automated ML) is incorrect because automated ML is a method for training and tuning, but it doesn't inherently prove accuracy.
* Option D (Validate the model by using the clinical data) is also incorrect if you use the same dataset for validation and training-it would not prove true accuracy.
Therefore, per Microsoft's official AI-900 study content, the verified correct answer is B. Split the clinical data into two datasets.

Correct Answer:

Explanation:

According to the Microsoft Azure AI Fundamentals (AI-900) study guide, the three main types of supervised and unsupervised machine learning models-classification, clustering, and regression-are used for distinct problem types depending on the structure of the data and the prediction goal.
* Clustering is an unsupervised learning technique used when the goal is to group items with similar characteristics without predefined labels. In this scenario, "Assign categories to passengers based on demographic data" implies automatically grouping passengers based on patterns such as age, income, or travel frequency, without any prior labeling. This directly maps to clustering, which discovers hidden groupings (for example, segmenting customers into categories like business travelers or vacationers).
* Regression is a supervised learning method used to predict continuous numerical values. The scenario
"Predict the amount of consumed fuel based on flight distance" is a classic regression problem because the output (fuel consumption) is a continuous variable dependent on another continuous variable (distance). Regression models, such as linear regression, are trained to estimate numeric outputs.
* Classification is also a supervised learning approach, but it predicts discrete categories or outcomes.
The scenario "Predict whether a passenger will miss their flight based on demographic data" involves a binary decision (missed or not missed), which is typical of classification tasks. These models learn from labeled examples to assign new instances to specific categories.
In summary, Clustering groups similar passengers, Regression predicts continuous numerical outcomes, and Classification determines categorical outcomes. This alignment precisely matches the definitions in Microsoft' s AI-900 learning objectives under "Describe common machine learning types and scenarios."

Correct Answer:

Explanation:

According to the Microsoft Azure AI Fundamentals (AI-900) official study guide and Microsoft Learn module "Identify features of regression machine learning", regression is a type of supervised machine learning used when the target variable (the value you want to predict) is a continuous numeric value.
In this scenario, the task is to predict how many hours of overtime a delivery person will work based on the number of orders received. Both the input (number of orders) and the output (hours of overtime) are numeric variables. Since the goal is to estimate a quantitative value rather than categorize or group data, this is a classic example of a regression problem.
Regression models analyze the relationship between variables to make numerical predictions. For example, the model might learn that each additional 20 orders increases overtime by about two hours. Common algorithms used for regression include linear regression, decision tree regression, and boosted regression models. These models produce outputs such as "expected overtime = 5.6 hours," which are continuous numeric results.
To contrast with the other options:
* Classification is used for predicting categories or labels, such as "overtime required" vs. "no overtime," or "high-risk" vs. "low-risk." It deals with discrete outputs rather than continuous numbers.
* Clustering is an unsupervised learning approach used to group similar data points based on shared characteristics, such as grouping delivery staff by performance patterns or customer types.
As emphasized in Microsoft's Responsible AI and Machine Learning Fundamentals learning paths, regression models are ideal for numeric forecasting problems such as predicting sales, revenue, demand, or working hours.
Therefore, the correct answer is: Regression.
Reference:Microsoft Learn - Identify the types of machine learning models: Regression, Classification, and Clustering (AI-900 Learning Path)

Correct Answer: A  🗳️

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