25 to 69 beats per minute. Let x be a random variable that represents the resting heart rate for an adult horse. Assume that x has a distribution that is approximately normal. USE SALT (a) The empirical rule indicates that for a symmetric and bell-shaped distribution, approximately 95% of the data lies within two standard deviations of the mean. 95% -20 4+20 Therefore, a 95% range of data values extending from 20 to +20 is often used for "commonly occurring" data values. Note that the interval from 20 to + 20 is 40 in length. This leads to a "rule of thumb" for estimating the standard deviation from a 95% range of data values. Estimating the standard deviation For a symmetric, bell-shaped distribution, range high value - low value standard deviation = 4 where it is estimated that about 95% of the commonly occurring data values fall into this range. Use this "rule of thumb" to estimate the standard deviation of x distribution (in beats per minute). beats per minute 11 (b) What is the probability that the heart rate is less than 29 beats per minute? (Round your answer to four decimal places.) 0.0505 (c) What is the probability that the heart rate is greater than 61 beats per minute? (Round your answer to four decimal places.) 0.10156 (d) What is the probability that the heart rate is between 29 and 61 beats per minute? (Round your answer to four decimal places.) x (e) A horse whose resting heart rate is in the upper 10% of the probability distribution of heart rates may have a secondary infection or illness that needs to be treated. What is the heart rate corresponding to the upper 10% cutoff point of the probability distribution? (Round your answer to the nearest whole number.)