The unit costs of 10 different kinds of cereal are shown.

$0.12, $0.15, $0.18, $0.29, $0.12, $0.55, $0.20, $0.24, $0.28, $0.17

Identify the outlier in the data set. Find the mean, median, and mode(s) of the data set without the outlier. Round to the nearest cent.