Histogram vs bar chart distinction in Matplotlib - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Difference between histogram and bar chart

Which statement correctly describes the main difference between a histogram and a bar chart?

A Histograms and bar charts are the same and can be used interchangeably for any data type.

B A histogram uses separated bars to show categorical data, while a bar chart uses adjacent bars for continuous data.

C Both histogram and bar chart show categorical data but histograms use colors to differentiate bars.

D A histogram shows the frequency distribution of continuous data using adjacent bars, while a bar chart displays categorical data with separated bars.

💡 Hint

Think about whether the data is continuous or categorical and how bars are placed.

Histograms group continuous data into bins with adjacent bars showing frequency. Bar charts show separate bars for categories.

❓ Predict Output

intermediate

Output of histogram code with matplotlib

What will be the output of this code snippet?

Matplotlib

import matplotlib.pyplot as plt
import numpy as np

data = np.random.normal(0, 1, 1000)
plt.hist(data, bins=5)
plt.show()

A A scatter plot of 1000 points around zero.

B A plot with 5 separated bars each representing a category.

C A plot with 5 adjacent bars showing frequency of data in 5 ranges.

D A line plot showing data values sorted.

💡 Hint

Look at the function used: plt.hist and the bins parameter.

plt.hist creates a histogram with bars adjacent representing frequency counts in bins.

❓ data_output

advanced

Data output from bar chart data preparation

Given this data preparation code, what is the output of counts?

Matplotlib

categories = ['A', 'B', 'C']
values = [10, 15, 7]
counts = dict(zip(categories, values))
print(counts)

A {'A': 10, 'B': 15, 'C': 7}

B {10: 'A', 15: 'B', 7: 'C'}

C ['A', 'B', 'C', 10, 15, 7]

D Error: cannot zip lists of different lengths

💡 Hint

Think about what zip and dict do together.

zip pairs elements from two lists by position, then dict creates key-value pairs.

❓ visualization

advanced

Identify the plot type from description

You see a plot with bars touching each other representing ranges of ages and their counts. What type of plot is this?

A Bar chart

B Histogram

C Pie chart

D Line chart

💡 Hint

Bars touching usually mean continuous data grouped in bins.

Histograms show continuous data grouped in bins with adjacent bars.

🔧 Debug

expert

Why does this bar chart code raise an error?

What error does this code raise and why?

import matplotlib.pyplot as plt
categories = ['X', 'Y', 'Z']
values = [5, 7]
plt.bar(categories, values)
plt.show()

A ValueError: x and height must have same length because categories and values differ in length.

B TypeError: categories must be numbers, not strings.

C SyntaxError: missing colon after plt.bar call.

D No error, the plot shows bars for X and Y only.

💡 Hint

Check if the lists passed to plt.bar have the same length.

plt.bar requires x and height lists to be the same length. Here, categories has 3 items but values has 2.