The deflection temperature (°F) of two types of plastic pipe under a specified load is investigated with two random samples of size 15 each. Assume the populations have equal variances. Obtain a 90% confidence interval for the difference in the true mean deflection temperatures (Type 1 minus Type 2). Type 1: 206, 188, 205, 187, 194, 193, 207, 185, 189, 213, 192, 210, 194, 178, 205 Type 2: 177, 197, 206, 201, 180, 176, 185, 200, 197, 192, 198, 188, 189, 203, 192.

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