I need help formulating both hypotheses in words and transferring them into a null and research hypothesis set. 15 out of 25 items are cheaper at Walmarts than Walgreens. 25-15=10 items cheaper at Walgreens than Walmarts.

Null hypothesis in words: Hence the number of items that are cheaper at walmart than walgreens is 15? (Not sure if this is correct)

Alternative hypothesis in words: ?

Null hypothesis in symbols: mu=15

Alternative hypothesis in symbols: mu does not equal 15