Tire pressure/psi 33 35 31 34 27 25 31 28 30 33 30 31 29 32 28 1 ratio What level of measurement is tire pressure in pounds per square inch? 2 15 Find the sample size n for the tire pressure data. 3 25 Find the minimum tire pressure. 4 35 Find the maximum tire pressure. 5 10 Find the range of the tire pressure. 6 31 Find the median tire pressure. 7 31 Find the mode for the tire pressure. 8 30.47 Find the sample mean tire pressure. 9 2.75 Find the sample standard deviation for the tire pressure. 10 0.0902 Find the sample coefficient of variation CV. 11 2 Width 12 Bins (x) Frequency (f) Rel. Freq. p(x) 27 2 0.133 29 3 0.200 31 5 0.333 33 3 0.200 35 2 0.133 Sum: 15 1 13 Sketch a relative frequency histogram 14 symmetric What is the shape of the distribution? Calculation of Mean from Frequency Table Mean from frequency distribution Grade bins Freq RF or P(x) x*p(x) 168 112 0.05 7.85 316 658 0.27 86.75 464 1172 0.49 226.87 612 332 0.14 84.77 760 123 0.05 39 Sums: 2397 1 445.23 15 445.23 What is the mean grade for the 2397 tires? Linear regression Linear regression Pressure/PSI Load/lbs 20 992 23 1062 26 1123 29 1183 32 1243 35 1302 16 20.5 Calculate the slope of the linear trend line. 17 586.95 Calculate the y-intercept for the data. 18 positive Is the correlation positive, negative, or neutral? 19 0.9996 Determine the correlation coefficient r. 20 high (or perfect) Is the correlation none, low, moderate, high, or perfect? 21 linear Does the relationship appear to be linear or non-linear? 22 0.9992 Determine the coefficient of determination. 23 99.92% What % in the variation in pressure variable accounts for the variation in load? 24 1099.57 A tire with an inflation of 25 psi could be expected to bear what load in pounds? 25 33.99 A load of 1284 pounds would require what inflation pressure? 26 Tire would blow A tire with an inflation of 100 psi could be expected to bear what load in pounds? Normal curves 27 C Which of the following curves is a normal curve? For the following normal distribution determine: 28a 5.5 What is the mean? 28b 2.2 What is the standard deviation?