For a standard normal distribution, which of the following expressions must always be equal to 1?
pzs-a) - p(-aszsa) - p(z2a)
pizs-a) - p(-aszsa)+ p(z? a)
o p(zs-a)+ p(-aszsa)- p(zea)
p(zs-a)+p(-aszka)+p(728)

It costs 4.25 for 1 pound of roast beef. how much will it cost to purchase 2.5 pounds of roast beef? round to nearest cent

The spring the owner of a sporting good store decreases the price of winter gloves from $10 to $8 each increases the price of swimming goggles from $8 to $10 without doing the math you think the percent decrease in the price of the gloves the same as the percent increase of the goggles explain why or why not

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?