Age (yr) when award was won Frequency 5-9 28 10-14 34 15-19 20-24 25-29 30-34 12262.

A research study investigates the occurrence of extra heartbeats between untrained and trained older patients at risk for heart attack. Researchers decide to test whether there is a significant difference in the number of extra beats depending on training status. They obtain measurements over 10 minutes, summarized below. What did they find? If there is a significant difference, how big of one is there? (Provide a range.) dfadi = 25 (if needed) Status # patients Untrained 43 Mean # extra beats/10 min 72.46 32.35 Standard Deviation Minimum # extra beats Maximum # of extra beats Skew Kurtosis 28 165 -0.21 0.62 Trained 21 169.50 62.93 66 266 0.13 -0.1

A biologist exposed a certain type of bacteria to gamma radiation to see how long they would live. He gathered data on the survival time of a number of bacterial cells and organized the data into the histogram below. Use the histogram to construct a frequency table. (The relative frequencies should be in decimal form.) 60+ 50 40 30 10 440 282 Survival Time (in Seconds) 45 124 203 361 519 Survival Time of Bacteria upon Exposure to Gamma Radiation Frequency Survival Time (in Seconds) Relative Frequency 45-124 124-203 203-282 282-361 361-440 440-519 Frequency 20

An electroencephalogram (EEG) is a tracing of brain waves recorded by an electroencephalogranh Neurologists have found that the peak EEG frequency in normal children increases with age in Ph. study (reported in Science, 1982), 287 normal children ranging from 2 to 16 years old were instructed to hold a 65-gram weight in the palm of their outstretched hand for a brief but unspecified time The peak EEG frequency (measured in hertz) was then recorded for each child. The children we grouped according to age, and the average peak frequency for each age group was recorded. The data appear in the accompanying table. AVERAGE PEAK EEG FREQUENCY AVERAGE PEAK EEG FREQUENCY AGE AGE х, уеars Y, hertz х, уears y, hertz 5.33 10 7.28 ndling. 3 5.75 11 7.06 4 5.80 12 7.60 5 5.60 13 7.45 6 6.00 14 8.23 7 5.78 15 8.50 8 5.90 16 9.38 9. 6.23 a. Construct a scattergram for the data. b. Find the least squares prediction equation. c. Graph the least squares line on the scattergram. d. Use the least squares…