Descriptive statistics review in Data Analysis Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to calculate the mean of the list 'data'.

Data Analysis Python

mean_value = sum(data) / [1]

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Amin(data)

Bsum(data)

Cmax(data)

Dlen(data)

Attempts:

3 left

💡 Hint

Common Mistakes

Dividing by sum(data) instead of the number of elements.

Using max or min instead of the count of elements.

The mean is the sum of all values divided by the number of values, which is given by len(data).

2fill in blank

medium

Complete the code to calculate the median of the sorted list 'data_sorted'.

Data Analysis Python

n = len(data_sorted)
median = (data_sorted[n // 2] if n % 2 != 0 else (data_sorted[n // 2 - 1] + data_sorted[[1]]) / 2)

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An // 2

Bn // 2 + 1

Cn // 2 - 1

Dn // 2 - 2

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong index for the second middle element.

Confusing integer division with float division.

For even number of elements, the median is the average of the two middle values at positions n//2 - 1 and n//2.

3fill in blank

hard

Fix the error in the code to calculate the variance of the list 'data'.

Data Analysis Python

mean = sum(data) / len(data)
variance = sum((x - mean)[1] for x in data) / len(data)

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A* 2

B** 2

C^ 2

D* * 2

Attempts:

3 left

💡 Hint

Common Mistakes

Using '^' which is bitwise XOR, not exponentiation.

Using '* 2' which doubles instead of squares.

To calculate variance, subtract the mean from each value, square the result using ** 2, then average.

4fill in blank

hard

Fill both blanks to create a dictionary of word lengths for words longer than 3 characters.

Data Analysis Python

lengths = {word: [1] for word in words if len(word) [2] 3}

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Alen(word)

B>

C<

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using the word itself as the value instead of its length.

Using '<' instead of '>' in the condition.

The dictionary comprehension maps each word to its length using len(word). The condition filters words longer than 3 using >.

5fill in blank

hard

Fill all three blanks to create a dictionary of uppercase words and their lengths for words longer than 4 characters.

Data Analysis Python

result = [1]: [2] for w in words if len(w) [3] 4

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Aw.upper()

Blen(w)

C>

Dw.lower()

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase instead of uppercase for keys.

Using '<' instead of '>' in the condition.

The dictionary comprehension uses the uppercase word as the key with w.upper(), the length as the value with len(w), and filters words longer than 4 with >.