Q1) A sample of n = 9 has mean of M = 10. One person with score of X = 2 is removed from sample. Determine the value of new sample mean?
From the knowledge of n and M get the sum of the scores. Then subtract 2 from this sum and divide by the new n=8.
Q2) Does it ever seem to you that weather is nice in the work week, but lousy on weekend? Cerveny and Balling (1998) have confirmed that this is not your imagination; pollution accumulating during work week most probable spoils weekend weather for people on Atlantic coast. Let the following hypothetical data illustrating daily amount of rainfall for 10 wks in the summer.
Rainfall on Weekdays 1.2, 0.6, 0.0, 1.6, 0.8, 2.1, 0.2, 0 .9, 1.1, 1.4
Rainfall on Weekends 1.5, 2.0, 1.8, 1.5, 2.2 2.4, 0.8, 1.6, 1.2, 1.7
a) Compute average daily rainfall in the week and for weekends. Get the average of weekdays' rainfalls and average of weekend's rainfalls.
b) Based on 2 means, does there appear to be the pattern in data? Based on part (a) make your conclusion.