How to Carry Forward all but one?

Your instincts are correct. Use JavaScript to hide the row with the 4th variable (i.e., statement). If you are NOT using Simple layout:

Qualtrics.SurveyEngine.addOnload(function() {
	jQuery("#"+this.questionId+" th.c1[id$=\\~4]").closest("tr").hide();
});

Qualtrics.SurveyEngine.addOnload(function() {
	jQuery("#"+this.questionId+" th.c1[id$=\\~4]").closest("tr").hide();
});

Hi TomG--I appreciate the reply. Unfortunately, I can’t get it to work. I’m not versed in JavaScript so it is almost definitely user error.

Qualtrics.SurveyEngine.addOnload(function() {
	jQuery("#"+this.questionId+" th.c1[id$=\\~4]").closest("tr").hide();
});

That probably means the id of the 4th statement doesn’t end in ~4. Depending on how the question is edited, the numbering doesn’t always start at 1 and may not be sequential. Use the Inspect feature of your browser to determine the id associated with the 4th statement (i.e., variable) then adjust ~4 to the correct number.

Qualtrics.SurveyEngine.addOnload(function() {
	jQuery("#"+this.questionId+" th.c1[id$=\\~4]").closest("tr").hide();
});

Heya! After lots of digging into the Inspect tool, I found the screenshot below.

Based on the image above, does this JavaScript look correct?

Qualtrics.SurveyEngine.addOnload(function() { jQuery("#"+this.questionId+" th.c1[id$=\\~x4]").closest("tr").hide(); });

Yes, that looks correct.

Bummer, for some reason it isn’t working. Thanks for trying. I’ll search for a different solution. 

@TerryFoster - I see the problem, you are using Simple layout.  In my initial response, I said if you are NOT using Simple layout. I’m not sure what type of matrix you have; it doesn’t look like a Likert. Since I don’t know, I’m guessing, but you can try changing closest("tr") to closest(".statement-container"). However, you may need to go further up the tree than what is shown in your screenshot.

Sorry--I’m using slider scales for these matrixes.

This should work:

Qualtrics.SurveyEngine.addOnload(function() {
	this.getQuestionContainer().querySelector(".slider-statement[id$=-x4]").style.display = "none";
});

Qualtrics.SurveyEngine.addOnload(function() {
	this.getQuestionContainer().querySelector(".slider-statement[id$=-x4]").style.display = "none";
});

Ugh, for some reason, it isn’t :(. Should I be copying/pasting the code as written by you?

Yes, the code as written worked for me for in me Simple layout on a Slider question with carryforward. So, I think you are using a different layout. Try:

Qualtrics.SurveyEngine.addOnload(function() {
	jQuery("#"+this.questionId+" label[for$=\\~x4]").closest(".slider-container").hide(); 
});

For future questions, you should include the layout type and question type at the start.