कक्षा 9–12Probability & Statisticsनियोजित
Sampling and statistical reasoning
Populations and samples, random sampling and bias, sampling variability, the normal distribution as a model, margin of error, correlation and regression lines, and why correlation is not causation.
math.prob.statistical-inference-intro
इस विषय का पाठ अभी लिखा नहीं गया है। नीचे दी गई रूपरेखा पाठ्यक्रम-मानचित्र का हिस्सा है और इसकी समीक्षा नहीं हुई है।
इस पर आधारित
12 अनिवार्य पूर्वापेक्षाएँ (बिल्कुल नीचे तक)
आप सीखेंगे
- Identify sources of bias in surveys and explain why random sampling helps.
- Use simulation to see how sample statistics vary, and interpret a margin of error.
- Fit and interpret a least-squares line and the correlation coefficient, distinguishing correlation from causation.
परिभाषा
- A population is the whole group of interest; a sample is the part that is observed.
- In a simple random sample of size n, every subset of the population of size n is equally likely to be chosen.
- The correlation coefficient r measures the strength and direction of a linear association; −1 ≤ r ≤ 1.
प्रमेय
- Larger random samples give less variable estimates; for a sample mean, the spread shrinks in proportion to 1/√n.
- Correlation, however strong, does not by itself establish causation; well-designed randomised experiments can provide evidence of causation.
- r = 0 means no linear association, not necessarily no relationship.
आम भ्रांतियाँ
- Thinking a large biased sample is better than a smaller random one.
- Misreading a 95% confidence interval: in the frequentist interpretation, 95% describes the long-run success rate of the method, not the probability that one computed interval contains the true value.
आगे ले जाता है
वैकल्पिक खोजें
- Probability theory The central limit theorem explains why sample means are approximately normally distributed, even when the data are not.
- ← Data displays and the mean as a fair share