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?