Question 471570
I'm going to use a table to solve this problem. Tables are usually given at the back of the book.


<font size=6><b>Standard Normal Probability Table:</b></font>

The table shows the area to the left of a z-score (area shown in red)<img src="http://i150.photobucket.com/albums/s91/jim_thompson5910/Algebra%20dot%20com/z_left_tail_small.png">



Now use the table to find the area to the left of -2.18 (it's shown in green and red below)

<table border=1><th>z</th><th>0.00</th><th>0.01</th><th>0.02</th><th>0.03</th><th>0.04</th><th>0.05</th><th>0.06</th><th>0.07</th><th><font color=green>0.08</font></th><th>0.09</th><tr><td><b>-3.4</b></td><td>0.0003</td><td>0.0003</td><td>0.0003</td><td>0.0003</td><td>0.0003</td><td>0.0003</td><td>0.0003</td><td>0.0003</td><td>0.0003</td><td>0.0002</td></tr>
<tr><td><b>-3.3</b></td><td>0.0005</td><td>0.0005</td><td>0.0005</td><td>0.0004</td><td>0.0004</td><td>0.0004</td><td>0.0004</td><td>0.0004</td><td>0.0004</td><td>0.0003</td></tr>
<tr><td><b>-3.2</b></td><td>0.0007</td><td>0.0007</td><td>0.0006</td><td>0.0006</td><td>0.0006</td><td>0.0006</td><td>0.0006</td><td>0.0005</td><td>0.0005</td><td>0.0005</td></tr>
<tr><td><b>-3.1</b></td><td>0.0010</td><td>0.0009</td><td>0.0009</td><td>0.0009</td><td>0.0008</td><td>0.0008</td><td>0.0008</td><td>0.0008</td><td>0.0007</td><td>0.0007</td></tr>
<tr><td><b>-3.0</b></td><td>0.0013</td><td>0.0013</td><td>0.0013</td><td>0.0012</td><td>0.0012</td><td>0.0011</td><td>0.0011</td><td>0.0011</td><td>0.0010</td><td>0.0010</td></tr>
<tr><td><b>-2.9</b></td><td>0.0019</td><td>0.0018</td><td>0.0018</td><td>0.0017</td><td>0.0016</td><td>0.0016</td><td>0.0015</td><td>0.0015</td><td>0.0014</td><td>0.0014</td></tr>
<tr><td><b>-2.8</b></td><td>0.0026</td><td>0.0025</td><td>0.0024</td><td>0.0023</td><td>0.0023</td><td>0.0022</td><td>0.0021</td><td>0.0021</td><td>0.0020</td><td>0.0019</td></tr>
<tr><td><b>-2.7</b></td><td>0.0035</td><td>0.0034</td><td>0.0033</td><td>0.0032</td><td>0.0031</td><td>0.0030</td><td>0.0029</td><td>0.0028</td><td>0.0027</td><td>0.0026</td></tr>
<tr><td><b>-2.6</b></td><td>0.0047</td><td>0.0045</td><td>0.0044</td><td>0.0043</td><td>0.0041</td><td>0.0040</td><td>0.0039</td><td>0.0038</td><td>0.0037</td><td>0.0036</td></tr>
<tr><td><b>-2.5</b></td><td>0.0062</td><td>0.0060</td><td>0.0059</td><td>0.0057</td><td>0.0055</td><td>0.0054</td><td>0.0052</td><td>0.0051</td><td>0.0049</td><td>0.0048</td></tr>
<tr><td><b>-2.4</b></td><td>0.0082</td><td>0.0080</td><td>0.0078</td><td>0.0075</td><td>0.0073</td><td>0.0071</td><td>0.0069</td><td>0.0068</td><td>0.0066</td><td>0.0064</td></tr>
<tr><td><b>-2.3</b></td><td>0.0107</td><td>0.0104</td><td>0.0102</td><td>0.0099</td><td>0.0096</td><td>0.0094</td><td>0.0091</td><td>0.0089</td><td>0.0087</td><td>0.0084</td></tr>
<tr><td><b>-2.2</b></td><td>0.0139</td><td>0.0136</td><td>0.0132</td><td>0.0129</td><td>0.0125</td><td>0.0122</td><td>0.0119</td><td>0.0116</td><td>0.0113</td><td>0.0110</td></tr>
<tr><td><font color=green><b>-2.1</b></font></td><td>0.0179</td><td>0.0174</td><td>0.0170</td><td>0.0166</td><td>0.0162</td><td>0.0158</td><td>0.0154</td><td>0.0150</td><td><font color=red><b>0.0146</b></font></td><td>0.0143</td></tr>
<tr><td><b>-2.0</b></td><td>0.0228</td><td>0.0222</td><td>0.0217</td><td>0.0212</td><td>0.0207</td><td>0.0202</td><td>0.0197</td><td>0.0192</td><td>0.0188</td><td>0.0183</td></tr>
<tr><td><b>-1.9</b></td><td>0.0287</td><td>0.0281</td><td>0.0274</td><td>0.0268</td><td>0.0262</td><td>0.0256</td><td> 0.0250</td><td>0.0244</td><td>0.0239</td><td>0.0233</td></tr>
<tr><td><b>-1.8</b></td><td>0.0359</td><td>0.0351</td><td>0.0344</td><td>0.0336</td><td>0.0329</td><td>0.0322</td><td>0.0314</td><td>0.0307</td><td>0.0301</td><td>0.0294</td></tr>
<tr><td><b>-1.7</b></td><td>0.0446</td><td>0.0436</td><td>0.0427</td><td>0.0418</td><td>0.0409</td><td>0.0401</td><td>0.0392</td><td>0.0384</td><td>0.0375</td><td>0.0367</td></tr>
<tr><td><b>-1.6</b></td><td>0.0548</td><td>0.0537</td><td>0.0526</td><td>0.0516</td><td>0.0505</td><td>0.0495</td><td>0.0485</td><td>0.0475</td><td>0.0465</td><td>0.0455</td></tr>
<tr><td><b>-1.5</b></td><td>0.0668</td><td>0.0655</td><td>0.0643</td><td>0.0630</td><td>0.0618</td><td>0.0606</td><td>0.0594</td><td>0.0582</td><td>0.0571</td><td>0.0559</td></tr>
<tr><td><b>-1.4</b></td><td>0.0808</td><td>0.0793</td><td>0.0778</td><td>0.0764</td><td>0.0749</td><td>0.0735</td><td>0.0721</td><td>0.0708</td><td>0.0694</td><td>0.0681</td></tr>
<tr><td><b>-1.3</b></td><td>0.0968</td><td>0.0951</td><td>0.0934</td><td>0.0918</td><td>0.0901</td><td>0.0885</td><td>0.0869</td><td>0.0853</td><td>0.0838</td><td>0.0823</td></tr>
<tr><td><b>-1.2</b></td><td>0.1151</td><td>0.1131</td><td>0.1112</td><td>0.1093</td><td>0.1075</td><td>0.1056</td><td>0.1038</td><td>0.1020</td><td>0.1003</td><td>0.0985</td></tr>
<tr><td><b>-1.1</b></td><td>0.1357</td><td>0.1335</td><td>0.1314</td><td>0.1292</td><td>0.1271</td><td>0.1251</td><td>0.1230</td><td>0.1210</td><td>0.1190</td><td>0.1170</td></tr>
<tr><td><b>-1.0</b></td><td>0.1587</td><td>0.1562</td><td>0.1539</td><td>0.1515</td><td>0.1492</td><td>0.1469</td><td>0.1446</td><td>0.1423</td><td>0.1401</td><td>0.1379</td></tr>
<tr><td><b>-0.9</b></td><td>0.1841</td><td>0.1814</td><td>0.1788</td><td>0.1762</td><td>0.1736</td><td>0.1711</td><td>0.1685</td><td>0.1660</td><td>0.1635</td><td>0.1611</td></tr>
<tr><td><b>-0.8</b></td><td>0.2119</td><td>0.2090</td><td>0.2061</td><td>0.2033</td><td>0.2005</td><td>0.1977</td><td>0.1949</td><td>0.1922</td><td>0.1894</td><td>0.1867</td></tr>
<tr><td><b>-0.7</b></td><td>0.2420</td><td>0.2389</td><td>0.2358</td><td>0.2327</td><td>0.2296</td><td>0.2266</td><td>0.2236</td><td>0.2206</td><td>0.2177</td><td>0.2148</td></tr>
<tr><td><b>-0.6</b></td><td>0.2743</td><td>0.2709</td><td>0.2676</td><td>0.2643</td><td>0.2611</td><td>0.2578</td><td>0.2546</td><td>0.2514</td><td>0.2483</td><td>0.2451</td></tr>
<tr><td><b>-0.5</b></td><td>0.3085</td><td>0.3050</td><td>0.3015</td><td>0.2981</td><td>0.2946</td><td>0.2912</td><td>0.2877</td><td>0.2843</td><td>0.2810</td><td>0.2776</td></tr>
<tr><td><b>-0.4</b></td><td>0.3446</td><td>0.3409</td><td>0.3372</td><td>0.3336</td><td>0.3300</td><td>0.3264</td><td>0.3228</td><td>0.3192</td><td>0.3156</td><td>0.3121</td></tr>
<tr><td><b>-0.3</b></td><td>0.3821</td><td>0.3783</td><td>0.3745</td><td>0.3707</td><td>0.3669</td><td>0.3632</td><td>0.3594</td><td>0.3557</td><td>0.3520</td><td>0.3483</td></tr>
<tr><td><b>-0.2</b></td><td>0.4207</td><td>0.4168</td><td>0.4129</td><td>0.4090</td><td>0.4052</td><td>0.4013</td><td>0.3974</td><td>0.3936</td><td>0.3897</td><td>0.3859</td></tr>
<tr><td><b>-0.1</b></td><td>0.4602</td><td>0.4562</td><td>0.4522</td><td>0.4483</td><td>0.4443</td><td>0.4404</td><td>0.4364</td><td>0.4325</td><td>0.4286</td><td>0.4247</td></tr>
<tr><td><b>0.0</b></td><td>0.5000</td><td>0.4960</td><td>0.4920</td><td>0.4880</td><td>0.4840</td><td>0.4801</td><td>0.4761</td><td>0.4721</td><td>0.4681</td><td>0.4641</td></tr>
</table>

From the table, we see that the area to the left of z = -2.18 is 0.0146



So P(z< -2.18) = 0.0146