Not always able to predict mean on the Distribute screen

[jessegreenberg]

This is a behavior question, I am not sure if it is a bug. To observe:

1. Got to distribute screen
2. Enable "Predict Mean"
3. Drag the pencil up and down.

There is no position where the mean displays a success. If this is the expected behavior, feel free to close.

For #270.

[jessegreenberg]

The code indicates that you should only be able to observe successes if the snacks are distributed, so maybe this is an intentional part of the model:

mean-share-and-balance/js/distribute/view/DistributeScreenView.ts

Lines 211 to 216 in 9fa448c

	const successStrokeColorWasSet = predictMeanLine.stroke === MeanShareAndBalanceColors.meanColorProperty;
	if ( snacksDistributed ) {
	const meanTolerance = 0.5;
	const roundedPrediction = Utils.roundToInterval( meanPrediction, 0.1 );
	const roundedMean = Utils.roundToInterval( meanValue, 0.1 );

[marlitas]

Yes, this is the expected behavior. I'll go ahead and assign to @amanda-phet since it was a question about behavior. Not sure if necessary to do anything about it, but want to make sure she is aware that it came up. Feel free to close if you want to leave as is.

[amanda-phet]

Yes this is intentional. If you place the line you are just making a prediction. This seemed clear in interviews so I think it's fine to keep as-is.