12. [0/2.5 Points] DETAILS MY NOTES DEVORESTAT9 1.4.049.S. PREVIOUS ANSWERS ASK YOUR TEACHER PRACTICE ANOTHER A study of the relationship between age and various visual functions (such as acuity and depth perception) reported the following observations on the area of scleral lamina (mm ) from human optic nerve heads: 2.65 2.61 2.69 3.83 2.33 2.68 3.84 4.20 3.96 4.27 3.53 4.51 2.45 3.64 2.77 3.53 3.05 L USE SALT (a) Calculate Ex, and Ex. 2. Ex; = 51.51 x mm2 Ex 2 = 170.6469 X mm (b) Use the values calculated in part (a) to compute the sample variance s and then the sample standard deviation s. (Round your answers to four decimal places.) 52 = 0.5123 x mm S= 0.7157 X mm2 Need Help? Read It Watch ItThe accompanying specific gravity values describe various wood types used in construction. 0.34 0.35 0.36 0.36 0.37 0.38 0.40 0.40 0.40 0.41 0.41 0.42 0.42 0.42 0.42 0.42 0.43 0.44 0.45 0.46 0.46 0.47 0.48 0.48 0.49 0.53 0.54 0.54 0.55 0.58 0.63 0.66 0.66 0.67 0.68 0.78 Construct a stem-and-leaf display using repeated stems. (Enter numbers from smallest to largest separated by spaces. Enter NONE for stems with no values.) Stem = tenths Leaf = hundredths 3L 4 3H 56678 4L 000112222234 4H 5667889 5L 34 4 5H 58 6L 3 6H 6678 7L NONE 7H 8Comment on any interesting features of the display. (Select all that apply.) The display is not symmetric and appears to be positively skewed. The data valus 0.78 is a possible outlier, The stem-and-leaf display shows that 0.45 is 2 good representative value for the data. The display is symmetric. There is 2 small amount of variation in the data. There is a reasonably large amount of variation in the data. The data value 0.324 is a possible outlier. The stem-and-leaf display shows that 0.55 is a good representative value for the data. * 9. [1.3/2.5 Points] DETAILS MY NOTES DEVORESTATY 1.3.036. PREVIOUS ANSWERS ASK YOUR TEACHER PRACTICE ANOTHER A sample of 26 offshore oil workers took part in a simulated escape exercise, resulting in the accompanying data on time (sec) to complete the escape: 286 351 356 360 279 425 321 293 401 373 374 370 362 267 3264 325 337 304 380 368 376 358 352 407 331 397 (a) Construct a stem-and-leaf display of the data. (Enter numbers from smallest to largest separated by spaces. Enter NONE for stems with no values.) Stems Leaves 32 (|15 v 33 (|17 v 34 35 (|[1268 v 36 ||02478 g 37 [|03469 v 38 ||6 v 39 (|0457 vy 40 (|17 v 41 42 How does it suggest that the sample mean and median will compare? O The display is negatively skewed, so the median will be greater than the mean. O The display is positively skewed, so the mean will be greater than the median. (O The display is negatively skewed, so the mean will be greater than the median. @ The display is reasonably symmetric, so the mean and median will be close. O The display is positively skewed, so the median will be greater than the mean. L4 (b) Calculate the values of the sample mean % and median . [Hint: Ix; = 9619.] (Round your answers to two decimal places.) x = (39161 sec =|3725 sec (c) By how much could the largest time, currently 425, be increased without affecting the value of the sample meadian? (Enter w if there is no limit to the amount.) o0 4 By how much could this value be decreased without affecting the value of the sample median? (Enter o if there is no limit to the amount.) UNDEFINED X (d) What are the values of x and when the cbservations are reexpressed in minutes? (Round your answers to two decimal places.) 6% Jx mn x= =621 min