between 332.13 and 343.87

Good job! The 95% confidence interval for the mean, μ, is x¯±2⋅σn√=338±2⋅44225√=38±.2⋅4415≈338±5.87=(332.13, 334.87)$\overline{x}\pm 2\cdot \frac{\sigma }{\sqrt{n}}=338\pm 2\cdot \frac{44}{\sqrt{225}}=38\pm .2\cdot \frac{44}{15}\approx 338\pm 5.87=(332.13, 334.87)$ .