Please help me i dont understand

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?

Rewrite the following quadratic functions in intercept or factored form. show your work. f(t) = 20t^2 + 14t - 12

The customer price index(cpi), which measures the cost of a typical package of customer goods, was 208.8 in 2011 and 244.1 in 2016.let x=11 corresponding to the year 2011 an estimate to cpi into 2013 and 2014. assume that the data can be modeled by a straight line and the trend to continue idenfinitely. use data points to find such a line and then estimate the requested quantities