Step 1: Calculate the 0.035 that you already know how to do.
Step 2: Calculate 1-0.035 = 0.965
Step 3: Look at the Z table and find 0.965 (or as close to this value as possible)
<span>Step 4: Look at the far left of the row containing 0.965 </span><span> 1.8</span>
<span>Step 5: Look at the top of the column containing 0.965 </span><span> 0.01</span>
<span>Step 6: Add these two values </span><span> 1.81</span>
<span>Step 6 is your z value that corresponds to that level of confidence.</span>
Pick A i add both 400 and 900 I get 1,300
