Can you help me with parts a through c. I get confused on the meaning of the wierd symbol.

4. Suppose the measurement of temperature at location A on July Ist at i-th year follows a normal distribution, X; ~ N(#, '). Suppose we have 11 years of observation, which leads to an average temperature of 77F and a standard deviation of 5F. We want to test if there is evidence that the true mean temperature at location A on July Ist is higher than 70F. (a) Write down the appropriate Null and Alternative hypotheses. (4 points) (b) Give the value of our test statistic, and state the distribution of it. (4 points) (c) Use the t-table to bound the p-value for this hypothesis test as we have shown in lecture. (4 points) (d) Assess the strength of evidence against Ho and write a one sentence conclusion in the context of the problem. (4 points)