# Algebra I – Unit 3 Review

It says which statement is true about the data set, is the mean equal to the mode the mean greater than the mode mean equal median and mean is less than median, so let’s just try to find each one. The mean is the average. So we have to add them all up and then divide by how many there are there’s seven, and so the mean is six. The mode is most often, which is seven. The median is the middle number, which is six, so does the mean equal the mode? No is the mean greater than the mode. No is the mean equal, the median yes number two, a bag contains four white marbles. Two blue marbles and six red marbles find the probability for choosing a marble that is not blue or its complement. Well, the probability of choosing a blue marble is two out of twelve oops, so probability of not choosing, it would be 10 out of 12, which is 5 6. number three. There are digits from 0 to 9. Randomly selected find the probability that the first number selected is a 5 or 7 that’s 2 out of 10 digits, because 0 through 9 is 10 numbers. The second number is a 2, which is 1 option out of 10, and the third number is a three which is one option: oh a three or nine, which is two options out of ten. If i do something and then i do something and then i do something, i multiply those ways together, this reduces to a fifth times a tenth times, a fifth so it’s, one out of five hundred, which is a number four.

If one point is randomly selected from the points inside, the rectangle shown find the probability of the nearest percent that the point is in the circle. The radius is eight pi r. Squared is when you find the area of something well, not something a circle. So 64 pi is the area of the circle. We have four of those well, we have four circles so the probability of a circle out of the entire thing, the entire thing is well. If this is eight, this is also eight, and this is also eight, and this is also eight, and this is also eight. The diameter is 16, so one side is 32. Therefore, this side is also 32, so it’s a 32 by 32 square 32 times 32. Is one zero? Two four sixty four times four is two five. Six out of pi can 256 go into 10 24. It can four times so this is going to be pi over four. The probability of getting a circle is pi over four okay number. Five. If you roll a number cube and get a two what’s, the probability you roll it again and get a 5. so what’s the probability i give a 5 given that i just rolled a 2 well it’s the same thing. If i just rolled a 5, the 2 had no effect on it. Rolling die, doesn’t affect other dies being rolled. This would be one out of six number six. This is how many ways can you name the hexagon using ursula one, two, three, four, five? Six.

So if i have a hexagon 2 3 4., what letter could i use to start it? Well, i have 6 to choose from so i could pick a once. I pick a then i have 5 to choose from let’s say i pick l, then i have four to choose from then i have three to choose from then i have two to choose from and then i have one if you multiply all your ways together. So that’s going to be 30 times 4, which is 120 times. 6 is 720 ways fundamental counting principle. A number cube is rolled in coins are tossed find the probability the number on the cube is less than three and the coins show the same size so that’s. The probability you’re less than three and its tails tails or the probability you’re less than three and your heads heads so for the first one, if you’re less than three, you are two out of six and then you are tails. And then you are tails. And then, if you’re less than three your heads and then your heads you’re going to cancel here and then you’ll get 1 out of 12 plus 1 out of 12, which is 2 12, which is 1 6. number 8. A number cube with sides labeled one through six – is rolled two times. The sum of the numbers that end face up is calculated what’s, the probability that the sum of the numbers is a three well.

If i roll one die and i roll another die let’s. Think of all the possibilities i could roll a one and then that means i’d have to rule a two to get a sum of three. I could roll a two and get a one that’s it so that’s, two out of six ways to roll the first six ways to roll the second 36 ways. So that’s a one and eighteenth chance: number nine, the weight and pounds of each wrestler on a high school wrestling team at the beginning of the season is listed below what is the lower quartile value, so we have to arrange them in order. 112. 130. 142. 150. 178, 206.. Okay, here’s the middle. The lower quartile is the median of the lower fifty percent, so it’s c um using the box and whisker plot shown below which percent of class two scored above a seventy five. So this is the middle. So if you scored above a 75 that’s 50, so 50 scored above it’s half the class number 11. The table below shows a cumulative frequency distribution of earners ages. According to the table, how many runners are in their 40s people in their 20s are eight peoples in their 20s and 30s were 18. people in their 20s through 40s or 25, so to go from 20s to 30s to go to 20s to 40s? That was an increase of seven people, so seven people must have been in their 40s here’s a stem and leaf plot.

It says what was the number? What was the number of median? It says what was the number of median number? It should just be. What is the median number a point scored by the football team, so we start with 6, 12, 13, 14, 17, 20, 23, 24 and you write it out and you cross off that way. You could say: 38. 6, 37. 12. 30. 13. 14. 28, be very careful which one you start: 17. 28, 20, 28. 23 27, both in the middle take the average be 24.. You ask 200 students to select their favorite sport and then record the results below based on the information in the graph. If you ask another 80 students to select their favorite sport, how many more would say basketball was their favorite sport over football, so out of 275 out of 200, said basketball, okay, 75 at 200, that’s, 37.5 percent, and then what you did ask was for football. It was 50 out of 200, which is 25 percent. Okay. Now, if you ask 80 students 0.375 times, 80 equals 30 students from the next 80., so 37.5 students liked basketball, then, probably around that you know that’s the best guess of the next 80 students would be about 30 and then of the next 80 students. 25 percent. Should like football, maybe 20., so that means that there’d be 10, more basketball. Okay, it says, use the following circle graph for questions: 14 17. Your monthly budget is displayed below on the average on average, your take home salaries two grand a month, all right.

So these are the percentages out of a hundred percent, we have 12 percent is drinks and food and 10 is medical, seven percent is entertainment and eight is saving and 33 is your housing cost? That means everything else is 30 all right. What money do you save for other expenses? Well, if it’s 30 that’s 30 out of 100, your other total is 2 000.. We don’t know how much so cross multiply. Do you have to do it this way? No, you could do cross multiply and solve, for you. Can do 0.30 times, 2 thousand so .30 times 2 600 dollars is what you save in others. How much money do you set aside for savings? Well, savings is eight percent, so you could do eight percent times two thousand or you could say eight out of a hundred is equal to what out of two thousand. When you do that point: zero. Eight times, two thousand you get one hundred sixty dollars, yeah. That seems about right, your salary increases by four hundred dollars. So now we have twenty four hundred. How much money do you set aside for savings? Now we know savings is eight percent, so we could do it this way we could say eight times. Twenty four hundred, divided by a hundred, is one ninety two, so we went from 160 to 192.. What is the least amount you would have to take home if you want to spend 175 on entertainment? Well, having entertainment be seven percent, so if entertainment is 7 out of 100 and you want it to be 175, what would your take home need to be? So you have 7x equals 17500 divided by 7.

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