Given two terms of the arithmetic​ sequence, a8=30 and a13=−15​, find a1 and d.

a1 = ?

Solve this problem! extra ! 3025/5.5 = a/90.75 / = fraction

In a survey of 1015 adults, a polling agency asked, "when you retire, do you think you will have enough money to live comfortably or not. of the 1015 surveyed, 534 stated that they were worried about having enough money to live comfortably in retirement. construct a 90% confidence interval for the proportion of adults who are worried about having enough money to live comfortably in retirement.

Given the diagram below, michael writes, "segment ac is congruent to segment ac." which of the following reasons allow him to write this statement?