Question

Loretta, who turns 91 this year, has heard that the mean systolic blood pressure among the elderly is 115 millimeters of mercury (mmHg), but she believes that the actual value

is higher. She bases her belief on a recently reported study of 10 randomly selected, elderly adults. The sample mean systolic blood pressure of the adults in the study was 131 mmHg, and the sample standard deviation was 21 mmHg. Assume that the population of systolic blood pressures of elderly adults is normally distributed. Based on the study, at the 0.05 level of significance, can it be concluded that µ, the mean systolic blood pressure among elderly adults, is greater than 115 mmHg?

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