Read the problem. 40% of the desserts at a bake sale are cookies. If 120 of the desserts are cookies, how
many desserts are at the bake sale in all?
Pick the model that represents the problem.
How many desserts are at the bake sale in all?

300

Step-by-step explanation:

The total number of desserts is x. we don't know what it is.

40% of all the desserts are cookies.

That is 40% of x.

We are told that 120 of the desserts are cookies.

That means that 40% of all desserts amount to 120.

40% of x = 120

0.4x = 120

Divide both sides by 0.4

0.4x/0.4 = 120/0.4

x = 300

In all there are 300 desserts.

it costs $20 to interview each person for a survey. find the cost to obtain a +- 3% margin of error.

step-by-step explanation:

copy and paste, put it in google

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.