Typo corrected in balloonplot #603

Job	Run time
build (ubuntu-latest, latest, regression)	6m 41s
build (ubuntu-latest, latest, regressionTS)	23m 14s
build (ubuntu-latest, latest, regressionLTSts)	9m 0s
build (ubuntu-latest, latest, regressionEXT)	10m 37s
build (ubuntu-latest, latest, graphics)	41m 23s
build (ubuntu-latest, latest, multivariate)	20m 30s
build (ubuntu-latest, latest, multivariate-clustering)	8m 45s
build (ubuntu-latest, latest, regression-clustering)	14m 58s
build (ubuntu-latest, latest, mixsim)	3m 47s
build (ubuntu-latest, latest, utilities)	9m 18s
build (ubuntu-latest, latest, tclustMULT)	21m 12s
build (ubuntu-latest, latest, tclustMULTgpcm)	28m 27s
	3h 17m 52s

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