What is a key difference between qualitative data and quantitative data when it comes to analysis methods?
- All types of data are analyzed in the same way
- Qualitative data is always easier to analyze
- Qualitative data typically requires textual analysis, while quantitative data can be analyzed mathematically
- Quantitative data can't be used for statistical analysis
Qualitative data often requires textual or thematic analysis, categorizing the data based on traits or characteristics. Quantitative data, being numerical, can be analyzed using mathematical or statistical methods.
Data that follows a _____ Distribution has its values spread evenly across the range of possible outcomes.
- Binomial
- Normal
- Poisson
- Uniform
Data that follows a Uniform Distribution has its values spread evenly across the range of possible outcomes.
What is the primary goal of Exploratory Data Analysis (EDA)?
- To confirm a pre-existing hypothesis
- To create an aesthetic representation of the data
- To make precise predictions about future events
- To understand the underlying structure of the data
The primary goal of EDA is to understand the underlying structure of the data, including distribution, variability, and relationships among variables. EDA allows analysts to make informed decisions about further data processing steps and analysis.
In _____ scaling, we scale the data between the 1st quartile (25th quantile) and the 3rd quartile (75th quantile).
- Min-Max
- Robust
- Standard
- Z-score
In Robust scaling, we scale the data between the 1st quartile (25th quantile) and the 3rd quartile (75th quantile). This approach minimizes the impact of outliers.
Can the IQR method be applied to multimodal data sets for outlier detection? Explain.
- No, it can only be applied to normally distributed data
- No, it only works with unimodal distributions
- Yes, but it may not be effective
- Yes, it works well with any distribution
The IQR method can be applied to multimodal datasets for outlier detection, but it may not be effective as it's based on percentiles which can be influenced by multiple modes.
A potential drawback of the Z-score method for outlier detection is that it assumes the data is _______ distributed.
- exponentially
- logistically
- normally
- uniformly
The Z-score method assumes that the data is normally distributed, which may not be the case with all datasets, and is a drawback.
If a distribution is leptokurtic, what does it signify about the data?
- The data has a high variance.
- The data is heavily tailed with potential outliers.
- The data is less outlier-prone.
- The data is normally distributed.
Leptokurtic distribution signifies that the data has heavy tails and a sharp peak, meaning there are substantial outliers (or extreme values). This kind of distribution often indicates that the data may have more frequent large jumps away from the mean.
Describe the impact of skewness and kurtosis on parametric testing.
- They can improve the accuracy of parametric testing.
- They can invalidate the results of parametric testing.
- They can reduce the variance in parametric testing.
- They do not impact parametric testing.
Skewness and kurtosis can invalidate the results of parametric testing. Many parametric tests assume that the data follows a normal distribution. If the data is highly skewed or has high kurtosis, these assumptions are violated, and the test results may not be valid.
Which of the following plot types is best used to visualize a single continuous variable?
- Pie chart
- Scatter plot
- Histogram
- Bar chart
A Histogram is the best option for visualizing a single continuous variable as it can provide a snapshot of data distribution, showing the center, spread and skewness of the dataset.
A business wants to understand how much revenue they will generate in the next quarter based on historical data. Which type of data analysis will you apply?
- All are equally suitable
- CDA
- EDA
- Predictive Modeling
Predictive Modeling would be the most suitable because it leverages historical data to predict future outcomes, which is exactly what the business needs.
In a PHP while loop, where is the condition tested?
- Before each iteration
- After each iteration
- At the beginning of the loop
- At the end of the loop
In a PHP while loop, the condition is tested before each iteration. Before executing the code block for each iteration, the condition is evaluated. If the condition evaluates to true, the code block will be executed. If the condition evaluates to false, the loop will be terminated, and the execution will continue with the code following the loop. The condition is checked at the beginning of each iteration to determine whether the loop should continue or not. Learn more: https://www.php.net/manual/en/control-structures.while.php
Are Parent constructors called implicitly inside a class constructor?
- Yes
- No
- Depends on the scenario
- Only in abstract classes
Parent constructors are not called implicitly inside a class constructor in PHP. You need to explicitly call the parent constructor using parent::__construct(). Learn more: http://php.net/manual/en/language.oop5.decon.php