Reference no: EM132856775

Flint residents were told that by running (flushing) their tap water for about 45 seconds, the lead levels in the water will drop significantly.

The data below on the lead levels in tap water for the homes for the initial draw and then for the draw from the same source after 45 seconds of flushing the water.

Did the average lead level reduce significantly after 45 seconds? Test this at 5% and 1% level of significance.

a) State the null and alternate Hypotheses.

b) What is the p-value?

c) Did the average lead level reduce significantly at 5% level of significance? Why or why not?

d) Did the average lead level reduce significantly at 1% level of significance? Why or why not?

e) Please explain your findings in a clear language intended for a non-technical audience. Should the Flint residents be running their tap water for 45 seconds prior to drinking it?

SampleID Zip Code Ward Pb Bottle 1 (ppb) - First Draw Pb Bottle 2 (ppb) - 45 secs flushing

1 48504 6 0.344 0.226
2 48507 9 8.133 10.77
4 48504 1 1.111 0.11
5 48507 8 8.007 7.446
6 48505 3 1.951 0.048
7 48507 9 7.2 1.4
8 48507 9 40.63 9.726
9 48503 5 1.1 2.5
12 48507 9 10.6 1.038
13 48505 3 6.2 4.2
15 48507 9 4.358 0.822
16 48505 5 24.37 8.796
17 48505 2 6.609 5.752
18 48503 7 4.062 1.099
19 48507 9 2.484 0.72
20 48507 9 0.438 1.046
21 48503 5 1.29 0.243
22 48504 6 0.548 0.622
23 48504 2 3.131 0.674
24 48504 6 120 239.7
25 48505 1 2.911 0.406
26 48505 5 16.52 10.26
27 48505 1 1.984 1.13
28 48503 7 5.367 2.474
29 48504 2 5.5 8.4
30 48506 4 0.639 0.223
31 48503 7 6.087 28.87
31 48503 7 10.32 13.47
33 48503 6 66.88 2.662
34 48505 1 20.41 3.543
35 48504 6 109.6 80.47
36 48503 8 5.06 3.406
37 48504 2 2.774 0.21
38 48505 3 4.453 3.679
39 48505 1 0.4 0.3
40 48529 9 0.974 0.142
41 48505 5 3.228 2.534
42 48505 2 12.55 4.132
43 48505 3 0.501 0.156
44 48504 2 2.448 0.373
45 48505 3 5.508 5.157
46 48504 6 1.293 0.441
47 48505 1 4.699 1.395
48 48504 6 6.093 2.682
49 48504 2 0.8 0.8
50 48503 5 1.626 1.332
51 48507 8 2.576 2.852
52 48504 1 2.362 0.467
53 48503 5 1.585 0.494
54 48506 4 3.058 1.808
55 48506 4 2.423 0.393
56 48503 8 30.91 42.58
57 48503 8 4.47 3.649
58 48505 1 2.172 1.76
59 48505 3 1.8 0.5
63 48503 5 0.965 0.166
65 48505 1 7.636 5.206
66 48506 3 3.158 1.948
67 48503 7 105.3 12.84
68 48506 3 4.476 0.355
69 48504 1 2.828 6.694
71 48503 5 2.481 3.86
72 48507 5 11.52 0.288
73 48507 8 3.784 0.292
74 48503 5 1.344 0.729
75 48504 6 11.93 9.645
76 48507 9 10.96 7.744
77 48504 6 3.341 0.555
78 48503 5 1.229 1.192
79 48503 6 6.3 1.1
79 48503 6 5.153 0.385
80 48504 6 6.054 0.927
82 48504 2 31.14 4.73
83 48504 6 102.7 9.894
84 48504 2 1.38 3.734
85 48505 3 1.132 2.17
87 48507 9 3.232 2.989
88 48532 8 0.507 2.315
90 48506 4 8.561 5.141
91 48505 3 9.997 0.983
92 48504 1 4.152 0.758
93 48504 2 75.82 11.65
95 48506 4 138.8 2.745
96 48507 9 0.8 0.2
97 48504 2 7.244 1051
98 48506 3 1.621 0.3
99 48505 1 1.032 0.363
100 48504 2 0.866 0.292
101 48504 2 2.525 0.59
102 48505 5 9.408 4.444
103 48505 0 0.739 4.883
104 48505 1 0.9 0.2
105 48504 2 1.403 0.142
106 48503 8 5.655 5.882
107 48505 2 31.06 8.578
108 48506 4 1.469 0.291
109 48505 1 23.85 2.301
110 48505 2 9.766 11.13
111 48505 1 4.69 0.953
112 48505 3 4.066 5.894
113 48505 1 0.846 0.455
114 48505 1 2.054 3.978
115 48506 7 3.744 5.592
116 48507 9 12.9 2.202
117 48505 1 0.543 0.183
118 48503 7 6.877 2.984
119 48505 1 0.552 0.19
121 48506 3 59 2.9
122 48506 4 0.349 0.13
123 48506 4 4.764 1.388
124 48506 4 0.832 0.284
125 48506 4 1.224 0.568
126 48507 9 15.9 3.7
127 48506 4 5.667 1.405
128 48506 4 3.564 2.767
129 48506 4 0.475 0.2
130 48507 9 5.3 0.5
131 48506 4 1.166 0.736
132 48506 4 0.684 0.306
133 48503 8 6.347 1.724
134 48507 9 10.56 5.672
135 48502 5 2.273 2.808
136 48505 1 1.571 1.265
137 48503 8 5.402 4.196
138 48504 6 43.19 7.688
139 48503 8 1.492 1.409
140 48503 5 66.24 17.75
141 48505 1 1.799 0.032
142 48503 8 1.861 1.355
143 48503 8 2.672 2.001
144 48505 1 3.741 1.211
145 48506 4 1.934 0.374
146 48506 4 27.05 0.902
147 48506 4 1.174 0.291
148 48507 9 2.325 1.099
149 48506 4 1.966 0.253
150 48506 4 1.959 0.438
151 48506 4 0.823 1.881
152 48506 4 11.2 7.553
153 48504 2 5.668 3.341
154 48506 4 6.261 1.316
155 48506 4 4.797 1.594
156 48506 4 0.64 0.905
158 48507 9 8.713 2.799
159 48507 9 2.544 1.099
161 48507 9 0.41 0.096
162 48503 7 32.85 35.76
163 48503 7 12.87 14.87
164 48503 8 38.02 38.7
165 48507 9 2.435 8.183
166 48507 9 2.997 1.867
167 48507 9 11 10.53
168 48507 9 6.219 12.33
169 48503 8 8.8 3.1
170 48504 6 8.071 0.947
171 48507 9 3.262 0.453
172 48503 8 2.267 0.541
173 48505 3 0.922 0.878
174 48504 6 27.02 31.25
176 48503 8 0.906 0.961
177 48507 9 2.85 6.862
178 48504 2 1.852 0.472
179 48506 4 5.35 1.328
180 48503 7 25.21 4.337
182 48504 6 15.55 3.962
183 48506 4 0.793 0.533
184 48506 4 5.068 0.683
185 48507 8 26.64 8.878
186 48506 4 1.867 0.165
189 48506 4 19.16 12.54
191 48503 5 28.7 12.7
192 48507 9 20.22 8.908
193 48507 8 2.9 0.6
194 48503 7 18.86 5.051
195 48507 9 2.816 0.324
196 48506 3 118.4 40.78
197 48506 3 27.45 0.939
198 48503 7 1.2 0.1
200 48506 4 4.681 0.755
201 48506 3 11.57 6.08
202 48532 8 6.557 0.289
203 48505 3 3.4 9.6
204 48504 6 0.7 0.2
205 48507 8 158 90.83
206 48506 4 0.977 0.47
207 48503 8 8.471 4.692
208 48507 9 11.47 23.15
209 48503 7 5.228 2.477
210 48507 9 0.956 0.196
211 48504 6 1.671 0.405
212 48507 9 1.152 0.708
213 48507 9 0.5 0.1
214 48503 5 10.74 2.331
215 48507 9 3.9 0.4
216 48507 9 2.149 0.368
217 48506 4 1.1 0.4
218 48507 9 7.087 9.467
219 48505 1 1.329 0.609
220 48507 9 6.2 0.7
221 48505 3 0.8 0.26
222 48503 8 9.3 9.7
223 48504 2 2.1 1.2
224 48505 1 4.563 3.106
225 48504 2 4.808 6.196
226 48504 2 0.753 2.526
227 48505 1 1.862 1.213
228 48503 7 1.183 0.366
229 48503 7 8.2 3.2
230 48504 6 3.679 0.498
231 48505 1 2.37 7.333
234 48504 2 0.828 1.318
235 48503 7 0.719 0.254
236 48504 1 2.822 1.221
237 48504 8 2.867 0.723
238 48503 7 2.332 3.588
240 48503 8 4.401 2.111
241 48504 6 2.708 2.238
242 48504 6 34.13 6.002
243 48503 7 5.218 2.614
244 48503 7 15.73 13.95
245 48504 6 3.045 2.744
246 48503 7 1.1 0.5
247 48503 7 1.386 0.288
248 48504 6 0.915 0.354
249 48504 6 2.145 0.345
250 48507 8 4.056 0.547
251 48503 7 1.668 1.508
252 48503 7 7.575 1.362
253 48507 8 5.59 4.306
254 48503 5 0.708 0.326
255 48504 6 1.701 4.397
256 48504 6 1.467 0.149
258 48504 2 2.582 259.8
259 48505 2 22.08 15.86
260 48507 8 16.51 2.024
262 48507 8 56.26 4.692
263 48504 6 2.433 1.334
264 48503 7 0.5 0.2
265 48504 6 29.13 11.57
266 48505 1 12.3 0.5
267 48504 6 3.445 0.29
268 48507 9 16.49 12.83
269 48503 7 3.365 2.45
270 48503 7 1.154 0.176
271 48507 9 13.53 21.91
272 48504 6 2.229 1.573
273 48503 7 28.91 5.471
274 48503 7 6.601 1.929
275 48507 9 0.948 0.27
276 48505 3 3.484 0.434
278 48503 7 1.888 0.359
279 48503 7 13.95 12.2
280 48504 6 6.27 4.036
281 48506 7 19.12 22.02
282 48507 9 1.633 0.465
283 48503 7 1.114 0.605
284 48503 7 3.9 0.558
285 48504 1 3.521 0.45
286 48507 9 3.832 0.794
287 48505 3 3.243 0.738
289 48503 7 0.99 0.25
290 48507 9 1.203 19.26
291 48506 3 2.261 0.102
292 48503 4 16.99 6.32
293 48503 7 3.322 2.559
294 48506 4 14.33 1.284
295 48503 7 18.11 20.21
296 48503 7 12.81 7.874
298 48503 7 1.083 0.322
299 48503 7 29.59 3.258
300 48505 1 4.287 4.345