The heart rate variability (hrv) of police officers was the subject of research published in a biology journal. hrv is defined as the variation in the time intervals between heartbeats. a measure of hrv was obtained for each in a sample of 303 police officers from the same city. (the lower the measure of hrv, the more susceptible the officer is to cardiovascular disease.) for the 62 officers diagnosed with hypertension, a 90% confidence interval for the mean hrv was (6.9,122.9). for the 241 officers that are not hypertensive, a 90% confidence interval for the mean hrv was (144.2,184.9). use this information to complete parts a through d below. a. what confidence coefficient was used to generate the confidence intervals? (type an integer or a decimal. do not round) b. give a practical interpretation of both of the 99% confidence intervals. c. when you say you are "99% confident," what do you mean? d. if you want to reduce the width of each confidence interval, should you use a smaller or larger confidence coefficient?