Suppose you have a data set x with 30 observations, where the mean is 13 and the
ID: 3202552 • Letter: S
Question
Suppose you have a data set x with 30 observations, where the mean is 13 and the standard deviation is 7. Two new data points, whose values are 17 and 14, are added to this set. What is the new mean? Suppose you have a data set {x_1, ..., x_n}, where x^bar = a, and you add two new data points: x_n+1 = a + c, and x_n+2 = a - c. Prove that your new mean is still a. x^bar = 320 and n = 44; what is sigma_i-1^n x_i? Prove that: sigma_i-1^n (x_i - x^bar) = 0. Suppose you have a data set x with 30 observations, where the mean is 13 and the standard deviation is 7. Two new data points, whose values are 17 and 9, are added to this set. What is the new variance (assume the mean does not change)?Explanation / Answer
25. here n=30 and mean=13
so sumx=30*13=390
now we need to rest two numbers 17 and 14 in sumx
so sumx=421
so new mean=421/32=13.156