You measure the lifetime of a random sample of 25 rats that are exposed to 10Sv of radiation (the equivalent of 1000 REM) for with the LD100 is 14 days. The sample mean is x=13.8 days. Suppose that the lifetimes for this level of exposure follow a normal distribution with unknown mean and standard deviation 0.75. you read a report that says "on the basis of random sample of 25 rats, a confidence interval for the true mean survival time extends from 13.45 to 14.15 days." The confidence level for this interval is?

Need now max recorded the heights of 500 male humans. he found that the heights were normally distributed around a mean of 177 centimeters. which statements about max’s data must be true? a) the median of max’s data is 250 b) more than half of the data points max recorded were 177 centimeters. c) a data point chosen at random is as likely to be above the mean as it is to be below the mean. d) every height within three standard deviations of the mean is equally likely to be chosen if a data point is selected at random.

Which of the following best describes the delian problem?

If the altitude is drawn to the hypotenuse of a right triangle, then the two triangles formed are similar to the original triangle and to each other. which set of triangles shows the similar triangles created by the altitude in the diagram?