She used copper for both sides of her fruit since she was looking for conductivity only, not generation of electricity. All measurements were taken from the same range, 2m, which my husband taught her about how the ranges are showed on the multimeter and interpreted. The mango average (we took 3 different readings) taken at the 2m range on the multimeter, which he showed her how that would convert into 6,667 ohms.
We purchased the fruits on the same day, let them sit on the counter until the next day so they would all be at room temperature so there wouldn't be temp. variations.
Pear - 17,000
I was surprised to see where lemon fit in on these readings, but I continue to try to help her understand the this is only showing that the pear is the better conductor, not necessarily a better generator of electricity. After she completed the experiments she cut open all the fruits to examine the insides. She noted the "walls" in each section of the fruits, the amount of pith, or skin as she called it, and the "juice pockets" that all are self contained in thin "walls". She deduced that all of those things were obstacles within the fruits that limited the flow of current. It was harder for the current to travel through all those extra things. In the pear, mango, and apple she noted that the insides appear with simple observation to be of one solid form. You can't see differences in the meat. It all appears the same. She thought pears were more firm, tougher to eat than apple, so those would be more dense. She'd never tried a mango before, so she didn't have that background knowledge as a comparison.