# Statistics: T-test Hypothesis Testing – #28665

Question: In the following experiment the researcher was interested in the side effects of radiation therapy on patents suffering cancerous lesions. In particular he was interested in the effect of radiation therapy on Mental dexterity. Each patient was scored (Pre test) on a mental dexterity test prior to treatment. They were again scored on a similar test (Post Test) one month after treatment began.

N1 = 16 were not given radiation and served as controls,

N2 = 19 were given radiation dosage in the range 25-50,

N3 = 18 were given radiation dosage in the range 75-100, and

N4 = 21 were given radiation dosage in the range 125-250.

The data were tabulated below:

 Pre test Post Test Treat 72 74 Control 58 57 Control 66 74 Control 51 56 Control 30 28 Control 48 40 Control 58 61 Control 51 50 Control 38 40 Control 56 56 Control 68 72 Control 36 38 Control 53 53 Control 65 72 Control 32 24 Control 64 62 Control 58 55 25-50 R 58 57 25-50 R 56 57 25-50 R 73 59 25-50 R 49 42 25-50 R 53 49 25-50 R 28 29 25-50 R 31 43 25-50 R 23 29 25-50 R 61 62 25-50 R 40 37 25-50 R 57 59 25-50 R 38 48 25-50 R 77 79 25-50 R 69 64 25-50 R 72 67 25-50 R 50 46 25-50 R 49 49 25-50 R 51 46 25-50 R 23 16 75-100 R 60 51 75-100 R 54 43 75-100 R 48 40 75-100 R 45 35 75-100 R 37 31 75-100 R 50 48 75-100 R 44 31 75-100 R 39 31 75-100 R 57 46 75-100 R 26 14 75-100 R 50 54 75-100 R 47 41 75-100 R 43 30 75-100 R 41 30 75-100 R 45 44 75-100 R 68 69 75-100 R 62 35 75-100 R 64 51 125-250 R 42 26 125-250 R 52 35 125-250 R 47 27 125-250 R 53 40 125-250 R 65 50 125-250 R 67 46 125-250 R 32 25 125-250 R 77 58 125-250 R 32 24 125-250 R 58 45 125-250 R 46 32 125-250 R 45 30 125-250 R 74 68 125-250 R 41 17 125-250 R 46 29 125-250 R 39 20 125-250 R 61 38 125-250 R 50 33 125-250 R 29 12 125-250 R 72 54 125-250 R 38 23 125-250 R

Analyze this data stating your conclusions