1. Select all the histograms that you want to make the same size.
2. Go to the "Format" tab in the Excel ribbon.
3. In the "Size" group, click on the "Size and Properties" button.
4. In the "Size and Properties" dialog box, make sure that the "Properties" tab is selected.
5. In the "Properties" tab, note down the values for "Height" and "Width".
6. Change the values for "Height" and "Width" to the same values for all the histograms.
7. Click "OK" to close the dialog box.
8. Now, all the histograms should be the same size.
9. Copy the histograms by selecting them and pressing "Ctrl+C".
10. Open the Word document and paste the histograms by pressing "Ctrl+V".
11. If the histograms are not the right size in Word, you can adjust them by clicking on them and dragging the sizing handles.

By following these steps, you can easily make all the histograms the same size in Excel and then paste them into Word without having to manually adjust each one.