2x9 checkout_system n mean new 1828 2279890 md 1655 2217148 ### Q3 \"'{r} ?t.test t.test(x : filter(v, checkout_system 2: y : filter(v, checkout_system :: alternative = c(\"two.sided")) median sd se total lower upper 2100.125 1316.097 30.78220 4167638 2219.56 2340.22 2090.870 1276.839 31.38609 3669381 2155.63 2278.67 Is average spending significantly higher in the treatment group? (The treatment group consists in the customers using the new checkout system.) Answer this question using a 2 sample, Z-tailed t-test with alpha set at .05. (Note that these are the default settings for the 't.test()' function when vectors are supplied for the x and y arguments.) 1)$spent, 0)$spent