What is the value of the digit 1 in the number 0.413

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.

Abby is collecting rainfall data. she finds that one value of the data set is a high-value outlier. which statement must be true? abby will use a different formula for calculating the standard deviation. the outlier will increase the standard deviation of the data set. the spread of the graph of the data will not change. abby will not use the mean when calculating the standard deviation.