Varians dan simpangan baku

Varians dan simpangan baku adalah dua cara paling umum untuk mengukur sebaran suatu variabel, dan Anda akan berlatih menghitung keduanya dalam latihan ini. Sebaran penting karena dapat membantu membentuk ekspektasi. Misalnya, jika seorang tenaga penjual menjual rata-rata 20 produk per hari, tetapi memiliki simpangan baku 10 produk, kemungkinan akan ada hari ketika ia menjual 40 produk, tetapi juga hari ketika ia hanya menjual satu atau dua. Informasi seperti ini penting, terutama saat membuat prediksi.

Pustaka dplyr dan ggplot2 sudah dimuat, dan food_consumption tersedia.

Latihan ini adalah bagian dari kursus

Pengantar Statistika di R

Latihan interaktif praktis

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Latihan ini adalah bagian dari kursus

Pengantar Statistika di R

SkillTag.level.intermediateSkillTag.label

4.8+

Mulai Kursus Gratis

Summary statistics gives you the tools you need to boil down massive datasets to reveal the highlights. In this chapter, you'll explore summary statistics including mean, median, and standard deviation, and learn how to accurately interpret them. You'll also develop your critical thinking skills, allowing you to choose the best summary statistics for your data.

Exercise 1: Apa itu statistika?Exercise 2: Statistik deskriptif dan inferensial Exercise 3: Klasifikasi tipe data Exercise 4: Ukuran pemusatan Exercise 5: Mean dan median Exercise 6: Rata-rata vs. median Exercise 7: Ukuran Sebaran Exercise 8: Varians dan simpangan baku

Latihan Saat Ini

Exercise 9: Kuartil, kuantil, dan kuintil Exercise 10: Menemukan pencilan menggunakan IQR

In this chapter, you'll learn how to generate random samples and measure chance using probability. You'll work with real-world sales data to calculate the probability of a salesperson being successful. Finally, you’ll use the binomial distribution to model events with binary outcomes.

Exercise 1: What are the chances?Exercise 2: With or without replacement?Exercise 3: Calculating probabilities Exercise 4: Sampling deals Exercise 5: Discrete distributions Exercise 6: Creating a probability distribution Exercise 7: Identifying distributions Exercise 8: Expected value vs. sample mean Exercise 9: Continuous distributions Exercise 10: Which distribution?Exercise 11: Data back-ups Exercise 12: Simulating wait times Exercise 13: The binomial distribution Exercise 14: Simulating sales deals Exercise 15: Calculating binomial probabilities Exercise 16: How many sales will be won?

It’s time to explore one of the most important probability distributions in statistics, normal distribution. You’ll create histograms to plot normal distributions and gain an understanding of the central limit theorem, before expanding your knowledge of statistical functions by adding the Poisson, exponential, and t-distributions to your repertoire.

Exercise 1: The normal distribution Exercise 2: Distribution of Amir's sales Exercise 3: Probabilities from the normal distribution Exercise 4: Simulating sales under new market conditions Exercise 5: Which market is better?Exercise 6: The central limit theorem Exercise 7: Visualizing sampling distributions Exercise 8: The CLT in action Exercise 9: The mean of means Exercise 10: The Poisson distribution Exercise 11: Identifying lambda Exercise 12: Tracking lead responses Exercise 13: More probability distributions Exercise 14: Too many distributions Exercise 15: Modeling time between leads Exercise 16: The t-distribution

In this chapter, you'll learn how to quantify the strength of a linear relationship between two variables, and explore how confounding variables can affect the relationship between two other variables. You'll also see how a study’s design can influence its results, change how the data should be analyzed, and potentially affect the reliability of your conclusions.

Exercise 1: Correlation Exercise 2: Guess the correlation Exercise 3: Relationships between variables Exercise 4: Correlation caveats Exercise 5: What can't correlation measure?Exercise 6: Transforming variables Exercise 7: Does sugar improve happiness?Exercise 8: Confounders Exercise 9: Design of experiments Exercise 10: Study types Exercise 11: Longitudinal vs. cross-sectional studies Exercise 12: Congratulations!