I need help with these questions

Ascatter plot with a trend line is shown below. which equation best represents the given data? y = x + 2 y = x + 5 y = 2x + 5

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

Rewrite the polynomial -9x5 + 36x4 + 189x3 in factored form.