Hypothesis testing is a method used to determine whether there is enough statistical evidence in a sample of data to infer that a certain condition is true for the entire population.
2024-10-20
Hypothesis testing is a method used to determine whether there is enough statistical evidence in a sample of data to infer that a certain condition is true for the entire population.
In hypothesis testing, we define two hypotheses:
\[ H_0: \mu = 70 \quad \text{(Null Hypothesis)} \] \[ H_A: \mu \neq 70 \quad \text{(Alternative Hypothesis)} \]
Where \(\mu\) is the population mean.
We will simulate a sample of 30 data points from a normal distribution with a mean of 71 and standard deviation of 5, and then perform a t-test.
set.seed(123) sample_data <- rnorm(30, mean = 71, sd = 5)
We perform a one-sample t-test to check if the mean of our sample is significantly different from 70.
t_test_result <- t.test(sample_data, mu = 70) t_test_result
## ## One Sample t-test ## ## data: sample_data ## t = 0.85364, df = 29, p-value = 0.4003 ## alternative hypothesis: true mean is not equal to 70 ## 95 percent confidence interval: ## 68.93287 72.59610 ## sample estimates: ## mean of x ## 70.76448
Now, let’s visualize some random data in 3D using Plotly.
Based on the p-value from the t-test, we decide to reject or fail to reject the null hypothesis.
\[ \text{If } p\text{-value} < \alpha, \text{ reject } H_0. \]
In this case, we have:
## [1] 0.4003008
Finally, here’s a slide that shows the R code used to create one of the plots (the histogram, for example):