Data Analyst Interview Resources
Join our telegram channel to learn how data analysis can reveal fascinating patterns, trends, and stories hidden within the numbers! 📊 For ads & suggestions: @love_data
Больше📈 Аналитический обзор Telegram-канала Data Analyst Interview Resources
Канал Data Analyst Interview Resources (@dataanalystinterview) языкового сегмента Английский является активным участником. Сейчас сообщество объединяет 52 319 подписчиков, занимая 3 326 место в категории Образование и 7 179 место в регионе Индия.
📊 Показатели аудитории и динамика
С момента создания невідомо проект демонстрирует стремительный рост, собрав аудиторию из 52 319 подписчиков.
Согласно последним данным от 12 июня, 2026, канал показывает стабильную активность. За последние 30 дней изменение числа участников составило 266, а за последние 24 часа — 27, при этом общий охват остаётся высоким.
- Статус верификации: Не верифицирован
- Уровень вовлечённости (ER): Средний показатель вовлечённости аудитории составляет 2.52%. В первые 24 часа после публикации контент обычно набирает 0.93% реакций от общего числа подписчиков.
- Охват публикаций: В среднем каждый пост получает 1 317 просмотров. В течение первых суток публикация набирает 485 просмотров.
- Реакции и взаимодействия: Аудитория активно поддерживает контент: среднее количество реакций на один пост — 3.
- Тематические интересы: Контент сосредоточен на ключевых темах, таких как sql, row, |--, dataset, visualization.
📝 Описание и контентная политика
Автор описывает ресурс как площадку для выражения субъективного мнения:
“Join our telegram channel to learn how data analysis can reveal fascinating patterns, trends, and stories hidden within the numbers! 📊
For ads & suggestions: @love_data”
Благодаря высокой частоте обновлений (последние данные получены 13 июня, 2026) канал поддерживает актуальность и высокий уровень охвата публикаций. Аналитика показывает, что аудитория активно взаимодействует с контентом, что делает его важной точкой влияния в категории Образование.
SELECT test_group, AVG(purchase_amount) AS avg_purchase
FROM ab_test_results
GROUP BY test_group;
Run a t-test to check statistical significance (Python)
from scipy.stats import ttest_ind
t_stat, p_value = ttest_ind(group_A['conversion_rate'], group_B['conversion_rate'])
print(f"T-statistic: {t_stat}, P-value: {p_value}")
🔹 P-value < 0.05 → Statistically significant difference.
🔹 P-value > 0.05 → No strong evidence of difference.
2️⃣ Forecasting & Trend Analysis
Forecasting predicts future trends based on historical data.
✔ Time Series Analysis Techniques:
Moving Averages (smooth trends)
Exponential Smoothing (weights recent data more)
ARIMA Models (AutoRegressive Integrated Moving Average)
✔ SQL for Moving Averages:
7-day moving average of sales
SELECT order_date,
sales,
AVG(sales) OVER (ORDER BY order_date ROWS BETWEEN 6 PRECEDING AND CURRENT ROW) AS moving_avg
FROM sales_data;
✔ Python for Forecasting (Using Prophet)
from fbprophet import Prophet
model = Prophet()
model.fit(df)
future = model.make_future_dataframe(periods=30)
forecast = model.predict(future)
model.plot(forecast)
3️⃣ KPI & Metrics Analysis
KPIs (Key Performance Indicators) measure business performance.
✔ Common Business KPIs:
Revenue Growth Rate → (Current Revenue - Previous Revenue) / Previous Revenue
Customer Retention Rate → Customers at End / Customers at Start
Churn Rate → % of customers lost over time
Net Promoter Score (NPS) → Measures customer satisfaction
✔ SQL for KPI Analysis:
Calculate Monthly Revenue Growth
SELECT month,
revenue,
LAG(revenue) OVER (ORDER BY month) AS prev_month_revenue,
(revenue - prev_month_revenue) / prev_month_revenue * 100 AS growth_rate
FROM revenue_data;
✔ Python for KPI Dashboard (Using Matplotlib)
import matplotlib.pyplot as plt
plt.plot(df['month'], df['revenue_growth'], marker='o')
plt.title('Monthly Revenue Growth')
plt.xlabel('Month')
plt.ylabel('Growth Rate (%)')
plt.show()
4️⃣ Real-Life Use Cases of Data-Driven Decisions
📌 E-commerce: Optimize pricing based on customer demand trends.
📌 Finance: Predict stock prices using time series forecasting.
📌 Marketing: Improve email campaign conversion rates with A/B testing.
📌 Healthcare: Identify disease patterns using predictive analytics.
Mini Task for You: Write an SQL query to calculate the customer churn rate for a subscription-based company.
Data Analyst Roadmap: 👇
https://t.me/sqlspecialist/1159
Like this post if you want me to continue covering all the topics! ❤️
Share with credits: https://t.me/sqlspecialist
Hope it helps :) =VLOOKUP("A2", B2:D10, 3, FALSE)
- XLOOKUP is more powerful, offering the flexibility to search both vertically and horizontally, and it doesn’t require the lookup value to be in the first column.
Example:
=XLOOKUP(A2, B2:B10, C2:C10)
Tip: Explain the limitations of VLOOKUP (like not being able to search left or needing sorted data for approximate matches) and how XLOOKUP overcomes them.
3. How do you create a PivotTable in Excel, and why is it useful?
A PivotTable allows you to summarize large amounts of data quickly. Here’s how to create one:
1. Select your data.
2. Go to the Insert tab and click on PivotTable.
3. Choose where to place the PivotTable.
4. Drag and drop fields into the Rows, Columns, Values, and Filters sections.
4. What is conditional formatting, and how do you use it?
Conditional formatting is used to change the appearance of cells based on their content. It helps highlight trends, patterns, and outliers.
For example, to highlight cells greater than 1000:
1. Select the range of cells.
2. Go to the Home tab, click on Conditional Formatting.
3. Choose Highlight Cell Rules > Greater Than and enter 1000.
4. Choose a format (e.g., cell color) to apply.
5. How do you handle large datasets in Excel without slowing it down?
Here are some strategies to improve efficiency:
- Turn off automatic calculations: Use manual recalculation to prevent Excel from recalculating formulas every time you make a change.
File > Options > Formulas > Calculation Options > Manual
- Use fewer volatile functions: Functions like NOW(), TODAY(), and INDIRECT() recalculate every time a change is made.
- Use tables instead of ranges: Structured references in tables are more efficient.
- Split large datasets: If feasible, split your data across multiple sheets or workbooks.
- Remove unnecessary formatting: Too much formatting can bloat file size and slow down processing.
6. How do you use Excel for data cleaning?
Data cleaning is one of the first and most important steps in data analysis, and Excel provides multiple ways to do this:
- Remove duplicates: Easily eliminate duplicate entries.
- Text to Columns: Split data in one column into multiple columns (e.g., splitting full names into first and last names).
- TRIM(): Remove extra spaces from text.
- FIND() and SUBSTITUTE(): For locating and replacing specific characters or substrings.
7. What are some advanced Excel functions you’ve used for data analysis?
Aside from the basics, some advanced Excel functions you might mention include:
- ARRAYFORMULA(): Allows multiple calculations to be performed at once.
- OFFSET(): Returns a range that is offset from a starting point.
- FORECAST(): Predicts future values based on historical data.
- POWER QUERY: For data extraction, transformation, and loading (ETL) tasks.
I have curated best 80+ top-notch Data Analytics Resources 👇👇
https://t.me/DataSimplifier
Like for more Interview Resources ♥️
Share with credits: https://t.me/sqlspecialist
Hope it helps :)
Уже доступно! Исследование Telegram 2025 — ключевые инсайты года 
