And yesterday, it was looking completely fine but now its looking like this
Problem 2: Statistics  Hypothesis Testing
Question: A sample of 50 students from a school has an average test score of 76 with a standard deviation of 8. Test the hypothesis that the mean score for the population is 75 at a 0.05 significance level.
Solution:

State the hypotheses:
[
H_0: \mu = 75 \quad \text{(null hypothesis)}
]
[
H_a: \mu \neq 75 \quad \text{(alternative hypothesis)}
] 
Calculate the test statistic (use a ttest because the population standard deviation is unknown):
[
t = \frac{\bar{x}  \mu}{s/\sqrt{n}} = \frac{76  75}{8/\sqrt{50}} = \frac{1}{8/\sqrt{50}} = \frac{1}{1.131} \approx 0.884
]