need help doing these type of problems, write legible, show clear working

The results from a statistics class' first exam are as follows: The average grade obtained on the exam by its 45 students is an 35, with a standard deviation of 15 points. Answer the following based on this information: Approximately how many people received a failing grade {less than 65)? 2 points Save Answer QUESTION 37 The results from a statistics class' rst exam are as follows: The average grade obtained on the exam by its 45 students is an 85, with a standard deviation of 15 points: Answer the following based on this information: What percentage of people received a grade between a 70 and a 91