Number of users for some internet service provider has always averaged five thousand with a standalone deviation of 800. after an equipment upgrade, the average number of users at 100 randomly selected moments of time is 5200. does it indicate at 5% level of significance that the mean number of users has increased

A3cm×3cm\greend{3\,\text{cm} \times 3\,\text{cm}} 3cm×3cm start color greend, 3, space, c, m, times, 3, space, c, m, end color greend rectangle sits inside a circle with radius of 4cm\blued{4\,\text{cm}} 4cm start color blued, 4, space, c, m, end color blued . what is the area of the shaded region? round your final answer to the nearest hundredth.