Student # # Correct Highest Accuplacer Score Accuplacer Placement Into Course Took Pre-Requisite Moved Up/Down Signed Waiver (Remained in 090) Return to Table of Contents
AR EA
4 9 61 56 X No Yes ACCUP
5 5 23 47 X No Yes
6 8 86 48 X No Yes Mean 7.286
8 11 94 53 X No Standard Error 0.685
10 3 32 56 X No Yes Median 8
12 7.5 77 46 X No Yes Mode 8
15 4 49 46 X No Yes Standard Deviation 3.140746
17** 8 110 55 X Yes/Up -107 No Sample Variance 9.864286
18 4 61 45 X No Yes Kurtosis -0.92562
19** 8 72 54 X No Yes Skewness -0.19013
21** 12 94 55 X No Range 11
22** 11 100 54 X No Minimum 1
24 11.5 63 51 X No Maximum 12
27 5 40 49 X No Yes Sum 153
29 10.5 72 60 X No Count 21
30 6 78 58 X No Yes
32 8 99 47 X No Yes
34 6 73 48 X No Yes Pre-Req
37 10.5 99 47 X No
38 4 51 47 X No Yes Mean 5.643
40 1 0 51 X No Yes Standard Error 0.670
2 5 43 22 X No Yes Median 5.25
3 3 28 38 X No Yes Mode 3
7 7 39 53 X No Yes Standard Deviation 2.507133
9 3 23 25 X No Yes Sample Variance 6.285714
11 5.5 46 33 X No Yes Kurtosis 0.370809
13 6.5 53 23 X No Yes Skewness 0.98626
14 6 44 32 X No Yes Range 8
16 7 24 29 X No Yes Minimum 3
20** 10 55 37 X No Maximum 11
23** 11 83 34 X No Sum 79
26 4 65 35 X No Yes Count 14
31 4 28 34 X No Yes
39 4 29 21 X No Yes
41 3 76 36 X No Yes
1 3 [1] No Yes
25 4 38 31 No Yes
28 5.5 85 23 No Yes
33 5 57 31 No Yes
35 3.5 24 34 No No
36 5 No Yes
Null Hypothesis is that means are the same.  H0: mean difference = 0
z-Test: Two Sample for Means
  ACCUP Pre-Req
Mean 7.286 5.643
Known Variance 3.141 6.286
Observations 21 14
Hypothesized Mean Difference 0
z 2.123
P(Z<=z) one-tail 0.017
z Critical one-tail 1.645
P(Z<=z) two-tail 0.034
z Critical two-tail 1.960  
Bec z=2.1 falls in critical region 1.96,  REJECT H0, i.e., means probably NOT the same.
[1]
ACT 19