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Unformatted text preview: 1 Statistics 2080 - practice midterm questions 1. Independent random samples were drawn from two normal populations assumed to have the same standard deviation, resulting in the following summary statistics. n 1 = 9 S 1 = 4 n 2 = 11 S 2 = 5 Calculate a pooled estimate of the common standard deviation of the two populations. 2. A study was carried out to assess the effect of a new medication in reducing blood pressure. Thirty subjects were enrolled in a trial, of which 15 were randomly allocated to receive a new treatement, while 15 received a control medication. After 16 weeks in the study, each sub- ject’s blood pressure was measured, leading to the following summary statistics: n T = 16 ¯ X T = 8 S 2 p = 25 n C = 9 ¯ X C = 12 Where μ T and μ C represent the mean blood pressure in the treatment and control groups, it is desired to test H : μ T = μ C against H A : μ T < μ C (a) What is the value of the test statistic?...
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- Statistics, bone mineral density, 21 degrees, 16 weeks