warning fix

app/src/main/java/net/pokeranalytics/android/calculus/Stat.kt

@@ -15,6 +15,7 @@ import net.pokeranalytics.android.util.extensions.formattedHourlyDuration
 import net.pokeranalytics.android.util.extensions.toCurrency
 import java.util.*
 import kotlin.math.exp
+import kotlin.math.pow
 
 class StatFormattingException(message: String) : Exception(message) {
 
@@ -92,7 +93,7 @@ enum class Stat(override var uniqueIdentifier: Int) : IntIdentifiable, RowRepres
 			}
 
 			val numerator = -2 * hourlyRate * bankrollValue
-			val denominator = Math.pow(hourlyStandardDeviation, 2.0)
+			val denominator = hourlyStandardDeviation.pow(2.0)
 			val ratio = numerator / denominator
 			return exp(ratio)