Question

1.(0.5) IF WE ARE GIVEN THE POPULATION STANDARD DEVIATION AND n > 30 DO WE USE THE z-VALUES OR t-VALUES? NOW SHOW WHAT YOU HAVE LEARNED SO FAR WITH DESCRIPTIVE AND INFERENTIAL STATISTICS. YOU ARE PROMOTING ONE I.T. EMPLOYEE AND HAVE TWO CANDIDATES THAT HAVE EACH TAKEN THE SAME 15 SECURITY EXAMS OVER THE PAST YEAR. YOU HAVE TWO FINALIST CANDIDATES WHO HAVE THE FOLLOWING SCORES. SO, WHICH ONE DO YOU PICK AND WHY? (EACH TEST HAD POSSIBLE SCORES RANGING FROM 0 TO 100) A 40 89 90 91 92 89 44 84 85 92 89 90 86 88 92 B 99 85 84 79 81 88 80 85 79 82 81 80 79 83 82

Answer 1

Result:

1.(0.5) if we are given the population standard deviation and n > 30 do we use the z-values or t-values?

Since population standard deviation is given, z-values can be used.

NOW SHOW WHAT YOU HAVE LEARNED SO FAR WITH DESCRIPTIVE AND INFERENTIAL STATISTICS. YOU ARE PROMOTING ONE I.T. EMPLOYEE AND HAVE TWO CANDIDATES THAT HAVE EACH TAKEN THE SAME 15 SECURITY EXAMS OVER THE PAST YEAR. YOU HAVE TWO FINALIST CANDIDATES WHO HAVE THE FOLLOWING SCORES. SO, WHICH ONE DO YOU PICK AND WHY? (EACH TEST HAD POSSIBLE SCORES RANGING FROM 0 TO 100).

A 40 89 90 91 92 89 44 84 85 92 89 90 86 88 92

B 99 85 84 79 81 88 80 85 79 82 81 80 79 83 82

Descriptive statistics
	A	B
n	15	15
mean	82.73	83.13
sample standard deviation	16.74	5.11
sample variance	280.07	26.12
minimum	40	79
maximum	92	99
range	52	20

Candidate B have larger mean and low variance. B have higher mean and also consistent.   So we pick candidate B.