Quantitative Methods for Business
Prob 1
| This is a graded assignment reflecting your own work only. Students are not permitted assistance from other students or tutors. | ||||||||
| 1. (4pts) The following table contains measurements of the inside diameters of machined parts (0.01 mm). | ||||||||
| Observation | ||||||||
| Sample | 1 | 2 | 3 | 4 | ||||
| 1 | 15 | 11 | 6 | 9 | a. Calculate the sample means for each of the 10 samples. | |||
| 2 | 14 | 4 | 10 | 6 | ||||
| 3 | 7 | 10 | 9 | 11 | ||||
| 4 | 8 | 6 | 9 | 13 | ||||
| 5 | 14 | 8 | 9 | 12 | ||||
| 6 | 9 | 10 | 7 | 13 | ||||
| 7 | 15 | 10 | 12 | 12 | ||||
| 8 | 14 | 16 | 11 | 10 | ||||
| 9 | 11 | 7 | 16 | 10 | ||||
| 10 | 11 | 14 | 11 | 12 | ||||
| b. Calculate the overall process mean, x-bar. | ||||||||
Prob 2
| This is a graded assignment reflecting your own work only. Students are not permitted assistance from other students or tutors. | ||||||||
| 2. (5pts) Data-entry clerks at a large insurance company key in thousands of insurance records each day. Samples | ||||||||
| of work of 20 experienced clerks is shown in the table below. 12 Records entered by each clerk were carefully | ||||||||
| examined to determine if they contained errors. | ||||||||
| Clerk | Sample Size | x-bar, Avg # errors per page | ||||||
| 1 | 12 | 0.50 | Process mean = 0.30 and process std deviation = 0.231. Calculate the | |||||
| 2 | 12 | 0.42 | 3-SEM upper and lower control limits for an x-bar control chart of data entry. | |||||
| 3 | 12 | 0.00 | [You don't need to plot a chart.] | |||||
| 4 | 12 | 0.08 | ||||||
| 5 | 12 | 0.33 | ||||||
| 6 | 12 | 0.17 | ||||||
| 7 | 12 | 0.42 | ||||||
| 8 | 12 | 0.25 | ||||||
| 9 | 12 | 0.25 | ||||||
| 10 | 12 | 0.17 | ||||||
| 11 | 12 | 0.50 | ||||||
| 12 | 12 | 0.08 | ||||||
| 13 | 12 | 0.00 | ||||||
| 14 | 12 | 0.58 | ||||||
| 15 | 12 | 0.42 | ||||||
| 16 | 12 | 0.33 | ||||||
| 17 | 12 | 0.83 | ||||||
| 18 | 12 | 0.25 | ||||||
| 19 | 12 | 0.00 | ||||||
| 20 | 12 | 0.33 | ||||||
| 240 | 0.30 |
Prob 3
| This is a graded assignment reflecting your own work only. Students are not permitted assistance from other students or tutors. | |||||||
| 3. (6pts) A pharmaceutical manufacturer must control the concentration of active ingredient in a chemical process. | |||||||
| The optimum concentration is 10% and the following data is collected in 12 sample sets. | |||||||
| Observation | |||||||
| Sample | 1 | 2 | 3 | ||||
| 1 | 10.22 | 10.31 | 9.79 | 10.11 | process mean = 10.16 | ||
| 2 | 10.25 | 10.33 | 10.12 | 10.23 | process std deviation = 0.35 | ||
| 3 | 10.37 | 9.92 | 10.80 | 10.36 | UCL = 10.67 | ||
| 4 | 10.46 | 9.94 | 10.26 | 10.22 | LCL = 9.65 | ||
| 5 | 10.06 | 9.39 | 9.66 | 9.70 | |||
| 6 | 10.59 | 10.15 | 10.31 | 10.35 | |||
| 7 | 10.82 | 10.80 | 10.23 | 10.62 | a. Construct/plot an x-bar control chart of the chemical process. | ||
| 8 | 9.79 | 10.14 | 10.20 | 10.04 | |||
| 9 | 10.52 | 9.50 | 9.43 | 9.82 | |||
| 10 | 10.13 | 10.69 | 10.15 | 10.32 | |||
| 11 | 9.88 | 10.32 | 10.31 | 10.17 | b. Is the process in control? Why or why not? | ||
| 12 | 10.00 | 10.10 | 9.92 | 10.01 | |||
Prob 4
| This is a graded assignment reflecting your own work only. Students are not permitted assistance from other students or tutors. | |
| 4. (4pts) A value, x = 18.8, is sampled from a normal distribution having mean = 32.7 and standard deviation = 6.4. | |
| a. Calculate the Z-score for x = 18.8 | |
| b. Explain the meaning of the Z-score value you calculated. | |
Prob 5
| This is a graded assignment reflecting your own work only. Students are not permitted assistance from other students or tutors. | ||||||
| 5. (6pts) An online advertiser measures the "stickiness" of its ads by the browse duration of a webpage. Browsing data is sampled | ||||||
| throughout the advertisement's run as a check of the host's system reliability. The following data is a small subset of such | ||||||
| a sampling of ad duration (in seconds). | ||||||
| Obs | Duration | |||||
| 1 | 0.539 | a. Calculate the sample mean and sample standard deviation of the 300 observations. | ||||
| 2 | 0.626 | |||||
| 3 | 2.752 | |||||
| 4 | 2.400 | |||||
| 5 | 4.825 | |||||
| 6 | 0.086 | |||||
| 7 | 2.370 | b. Assign a Z-score to each sample observation. | ||||
| 8 | 1.453 | |||||
| 9 | 5.836 | |||||
| 10 | 0.268 | |||||
| 11 | 3.935 | c. The advertiser classifies any duration greater than 3s distant as an outlier. | ||||
| 12 | 4.901 | Identify all 3s outliers in the data. | ||||
| 13 | 1.900 | |||||
| 14 | 0.428 | |||||
| 15 | 1.968 | |||||
| 16 | 9.174 | |||||
| 17 | 0.154 | |||||
| 18 | 0.829 | |||||
| 19 | 10.026 | |||||
| 20 | 0.554 | |||||
| 21 | 0.663 | |||||
| 22 | 0.152 | |||||
| 23 | 1.270 | |||||
| 24 | 0.061 | |||||
| 25 | 0.722 | |||||
| 26 | 5.246 | |||||
| 27 | 2.665 | |||||
| 28 | 1.208 | |||||
| 29 | 0.658 | |||||
| 30 | 2.374 | |||||
| 31 | 3.184 | |||||
| 32 | 1.504 | |||||
| 33 | 0.051 | |||||
| 34 | 0.618 | |||||
| 35 | 1.406 | |||||
| 36 | 0.910 | |||||
| 37 | 3.866 | |||||
| 38 | 1.462 | |||||
| 39 | 3.056 | |||||
| 40 | 3.554 | |||||
| 41 | 0.426 | |||||
| 42 | 1.586 | |||||
| 43 | 1.367 | |||||
| 44 | 0.344 | |||||
| 45 | 1.649 | |||||
| 46 | 0.234 | |||||
| 47 | 1.434 | |||||
| 48 | 1.725 | |||||
| 49 | 10.241 | |||||
| 50 | 2.539 | |||||
| 51 | 1.019 | |||||
| 52 | 0.281 | |||||
| 53 | 11.229 | |||||
| 54 | 8.038 | |||||
| 55 | 2.410 | |||||
| 56 | 8.192 | |||||
| 57 | 3.608 | |||||
| 58 | 3.619 | |||||
| 59 | 1.290 | |||||
| 60 | 1.145 | |||||
| 61 | 1.228 | |||||
| 62 | 6.668 | |||||
| 63 | 1.559 | |||||
| 64 | 4.799 | |||||
| 65 | 0.391 | |||||
| 66 | 13.961 | |||||
| 67 | 4.260 | |||||
| 68 | 2.087 | |||||
| 69 | 0.052 | |||||
| 70 | 1.767 | |||||
| 71 | 10.316 | |||||
| 72 | 4.562 | |||||
| 73 | 4.803 | |||||
| 74 | 5.993 | |||||
| 75 | 0.600 | |||||
| 76 | 0.891 | |||||
| 77 | 5.798 | |||||
| 78 | 1.318 | |||||
| 79 | 0.169 | |||||
| 80 | 1.311 | |||||
| 81 | 1.514 | |||||
| 82 | 0.414 | |||||
| 83 | 0.347 | |||||
| 84 | 2.682 | |||||
| 85 | 10.070 | |||||
| 86 | 2.362 | |||||
| 87 | 6.891 | |||||
| 88 | 2.625 | |||||
| 89 | 1.079 | |||||
| 90 | 2.864 | |||||
| 91 | 0.142 | |||||
| 92 | 1.254 | |||||
| 93 | 0.330 | |||||
| 94 | 0.431 | |||||
| 95 | 4.820 | |||||
| 96 | 4.098 | |||||
| 97 | 6.101 | |||||
| 98 | 5.278 | |||||
| 99 | 0.768 | |||||
| 100 | 0.966 | |||||
| 101 | 0.993 | |||||
| 102 | 2.849 | |||||
| 103 | 1.008 | |||||
| 104 | 1.509 | |||||
| 105 | 2.558 | |||||
| 106 | 3.516 | |||||
| 107 | 2.183 | |||||
| 108 | 5.345 | |||||
| 109 | 0.058 | |||||
| 110 | 6.516 | |||||
| 111 | 0.916 | |||||
| 112 | 1.568 | |||||
| 113 | 0.862 | |||||
| 114 | 3.710 | |||||
| 115 | 0.144 | |||||
| 116 | 1.721 | |||||
| 117 | 2.678 | |||||
| 118 | 9.186 | |||||
| 119 | 1.962 | |||||
| 120 | 0.234 | |||||
| 121 | 0.809 | |||||
| 122 | 0.874 | |||||
| 123 | 1.339 | |||||
| 124 | 0.003 | |||||
| 125 | 2.163 | |||||
| 126 | 1.514 | |||||
| 127 | 0.161 | |||||
| 128 | 3.060 | |||||
| 129 | 0.998 | |||||
| 130 | 7.047 | |||||
| 131 | 4.248 | |||||
| 132 | 2.060 | |||||
| 133 | 1.581 | |||||
| 134 | 0.947 | |||||
| 135 | 6.386 | |||||
| 136 | 5.013 | |||||
| 137 | 0.425 | |||||
| 138 | 11.361 | |||||
| 139 | 2.464 | |||||
| 140 | 1.191 | |||||
| 141 | 2.251 | |||||
| 142 | 0.878 | |||||
| 143 | 7.162 | |||||
| 144 | 2.293 | |||||
| 145 | 5.046 | |||||
| 146 | 5.380 | |||||
| 147 | 5.345 | |||||
| 148 | 0.809 | |||||
| 149 | 0.815 | |||||
| 150 | 2.406 | |||||
| 151 | 0.797 | |||||
| 152 | 1.246 | |||||
| 153 | 0.626 | |||||
| 154 | 2.141 | |||||
| 155 | 1.678 | |||||
| 156 | 2.389 | |||||
| 157 | 3.108 | |||||
| 158 | 1.070 | |||||
| 159 | 2.447 | |||||
| 160 | 4.763 | |||||
| 161 | 1.082 | |||||
| 162 | 0.524 | |||||
| 163 | 0.317 | |||||
| 164 | 4.896 | |||||
| 165 | 0.831 | |||||
| 166 | 2.649 | |||||
| 167 | 0.324 | |||||
| 168 | 1.071 | |||||
| 169 | 4.768 | |||||
| 170 | 2.534 | |||||
| 171 | 4.018 | |||||
| 172 | 1.671 | |||||
| 173 | 2.370 | |||||
| 174 | 0.883 | |||||
| 175 | 2.965 | |||||
| 176 | 2.145 | |||||
| 177 | 2.002 | |||||
| 178 | 4.583 | |||||
| 179 | 0.606 | |||||
| 180 | 0.906 | |||||
| 181 | 0.948 | |||||
| 182 | 1.372 | |||||
| 183 | 0.576 | |||||
| 184 | 6.386 | |||||
| 185 | 4.168 | |||||
| 186 | 0.579 | |||||
| 187 | 1.714 | |||||
| 188 | 2.676 | |||||
| 189 | 1.818 | |||||
| 190 | 0.208 | |||||
| 191 | 0.645 | |||||
| 192 | 0.899 | |||||
| 193 | 0.168 | |||||
| 194 | 10.641 | |||||
| 195 | 1.947 | |||||
| 196 | 2.712 | |||||
| 197 | 0.738 | |||||
| 198 | 0.389 | |||||
| 199 | 0.538 | |||||
| 200 | 12.829 | |||||
| 201 | 2.228 | |||||
| 202 | 18.299 | |||||
| 203 | 0.519 | |||||
| 204 | 4.247 | |||||
| 205 | 0.758 | |||||
| 206 | 0.774 | |||||
| 207 | 0.694 | |||||
| 208 | 0.127 | |||||
| 209 | 0.007 | |||||
| 210 | 2.558 | |||||
| 211 | 3.307 | |||||
| 212 | 8.520 | |||||
| 213 | 4.597 | |||||
| 214 | 0.453 | |||||
| 215 | 0.653 | |||||
| 216 | 6.452 | |||||
| 217 | 0.810 | |||||
| 218 | 2.791 | |||||
| 219 | 1.874 | |||||
| 220 | 3.646 | |||||
| 221 | 0.305 | |||||
| 222 | 0.614 | |||||
| 223 | 1.972 | |||||
| 224 | 2.963 | |||||
| 225 | 0.565 | |||||
| 226 | 7.966 | |||||
| 227 | 0.921 | |||||
| 228 | 0.399 | |||||
| 229 | 3.768 | |||||
| 230 | 1.921 | |||||
| 231 | 1.867 | |||||
| 232 | 0.713 | |||||
| 233 | 0.203 | |||||
| 234 | 0.280 | |||||
| 235 | 1.126 | |||||
| 236 | 2.345 | |||||
| 237 | 0.320 | |||||
| 238 | 2.451 | |||||
| 239 | 1.332 | |||||
| 240 | 1.616 | |||||
| 241 | 0.245 | |||||
| 242 | 0.143 | |||||
| 243 | 0.130 | |||||
| 244 | 7.927 | |||||
| 245 | 1.159 | |||||
| 246 | 1.239 | |||||
| 247 | 2.596 | |||||
| 248 | 8.418 | |||||
| 249 | 5.140 | |||||
| 250 | 2.552 | |||||
| 251 | 2.599 | |||||
| 252 | 2.272 | |||||
| 253 | 0.688 | |||||
| 254 | 1.507 | |||||
| 255 | 0.306 | |||||
| 256 | 2.696 | |||||
| 257 | 0.787 | |||||
| 258 | 2.536 | |||||
| 259 | 3.630 | |||||
| 260 | 0.347 | |||||
| 261 | 3.529 | |||||
| 262 | 1.199 | |||||
| 263 | 2.124 | |||||
| 264 | 1.612 | |||||
| 265 | 2.740 | |||||
| 266 | 2.858 | |||||
| 267 | 4.201 | |||||
| 268 | 5.368 | |||||
| 269 | 0.788 | |||||
| 270 | 0.701 | |||||
| 271 | 3.645 | |||||
| 272 | 1.454 | |||||
| 273 | 2.560 | |||||
| 274 | 0.504 | |||||
| 275 | 4.635 | |||||
| 276 | 6.288 | |||||
| 277 | 0.043 | |||||
| 278 | 1.570 | |||||
| 279 | 0.217 | |||||
| 280 | 0.906 | |||||
| 281 | 1.003 | |||||
| 282 | 0.581 | |||||
| 283 | 1.268 | |||||
| 284 | 1.384 | |||||
| 285 | 1.877 | |||||
| 286 | 1.065 | |||||
| 287 | 0.297 | |||||
| 288 | 2.647 | |||||
| 289 | 8.310 | |||||
| 290 | 7.065 | |||||
| 291 | 0.168 | |||||
| 292 | 0.734 | |||||
| 293 | 0.025 | |||||
| 294 | 2.619 | |||||
| 295 | 0.816 | |||||
| 296 | 6.008 | |||||
| 297 | 0.071 | |||||
| 298 | 0.323 | |||||
| 299 | 3.960 | |||||
| 300 | 0.011 | |||||
check values
| 1.a. Sample #2 sample mean = 8.5 |
| 2. UCL = 0.50 |
| 3. |
| 4. Z = -2.17 |
| 5.a. mean = 2.532 |
| 5.b. Obs #2, Z = -0.706 |