Are the numbers and patterns 16 1 respectively? 5cm, 162cm5 ... From the mode, group A scored 90 points, group B scored 70 points, and group A scored better; From the median point of view, the answers of the two groups (3) are not unique. For example, the median score of all ninth-grade girls can be selected first. There are 33 girls in Group A who have more than 80 points (including 80 points), and there are candidates in Group B. If it is not enough, 26 girls whose height is close to 162cm can be selected, so in Group A, S2 A = 172 (square score) can be obtained from variance. Judging from the high score, it is higher than 6. (1) A: The average value is 9? 6 years, mode 8 years, median 8? 5 years; The average is 9 points? 480 points, 20 in group A and 24 in group B; Among them, the full score of group A is less than that of group B. Because of the year, the mode is 4 years and the median is 8 years. In this respect, the scores of group B are mostly higher. (2) Company A uses the majority, and Company B uses the median of 6. (1) X A = 15 (cm), S2 A = X B = 15 (cm), S2 B = 35 (cm 2). (3) The answer to this question is not unique, just give reasons. For example, choose a company's product, because its mean, mode and median are close to 33, the product quality is better, S2 A < S2 B is relatively stable, and the first step is relatively stable and comfortable. The variance is 0, and walking feels smooth and comfortable, 4.4. 1.C2。 B3.24.S2 = 25。 D7。 Median 1700 yuan, mode 1600 yuan. The manager's introduction does not reflect the employee's monthly salary. 6. All kinds of data in the table of players in Group B are: 8. It is more appropriate to use 1700 yuan or 1600 yuan to express the specific evaluation: ① From the point of average and median, both groups of students answered 8 questions correctly and scored equally; Review question 2 From the perspective of most people, A is better than B; ③ In terms of variance, the scores of members in Group A are quite different, while those in Group B are relatively small; ④ From the excellent rate, there are 1 outstanding students in Group A than in Group B, and the sampling and general survey are 2. Scheme 4 is more reasonable because the selected sample is representative. (1) 3. Is the average 14? 4 years old, median and mode are 14 years old. 4. The standard deviation of the mean median mode is 5.2? 8 6. D7.A8.A9.10,32004 (ten thousand yuan) 5? 12? 62? 68.3 10. Incorrect. The average grade reflects the average level of the whole class and is easily influenced by abnormal values. When there are abnormal values, such as a few zeros, Xiao Ming may not be above the average. Did Xiao Ming's grade in 2006 belong to 6 (ten thousand yuan)? 53? 03? The level of 0 1 1.3 depends on whether his score is greater than the median. (2) It can be analyzed from the perspectives of mean, median, mode, standard deviation and variance (as long as it is meaningful). B 3 18; C scored 307 points in the exam, and B should be hired. For example, in terms of average, median and mode, the household income ratio in 2006 was 1 1. (1) The weighted average score of three people is A 29520202020204, but the gap has widened. (2) To strengthen the study of professional knowledge; Third, we should continue to work hard in these three areas, focusing on professional knowledge and work experience 4.5 12. (1) The median of A in the table is 7? 5. The average, median and hit times of B are 1. The variance or standard deviation is 2.400 3. ( 1) 1? 8 kg (2) 27,000 yuan is 7,7,04. The variance of annual rings in the eighth grade class is 3 (square annual rings), and the variance of annual rings in the eighth grade class is 2. From the aspects of mean, variance, median, and the number of shots above 9, it can be seen that A's score is better, and A's score is on the rise (5.3 (1), for example, x = 9, x = 3, x =-3, etc. 85. 1 (4) x ≥ 24。 ( 1) x ≥ 1 (2) x < 45.x > 2。 The smallest integer solution is 35. 1,2,3; 2,3, 4 7.A (3) < (4) > (5) > 5.3 (2) 4. 1。 ( 1) x ≤ 0 (2) x < 43 (3)。 80+ 16x < 54+20x4。 X < 72。 The nonnegative integer solution is 0, 1, 2, 3 (2). When x = 6, 80+ 16x = 176, 54+20x = when x = 7, 80+16x =192,54.
+20x = 194, Xiao Xia has 5 more deposits than Xiaoming. ( 1) x < 165 (2) x
Between 30 and 32 tons (including 30 and 32 tons) 56 3. Slightly 4. Slightly 5. C6。 As shown in Chapter 6, the graph and coordinates are 6.3 (1) 6.11. A (-2， 1)，B (2， 1)- 1) 1 . C2 . a '(3，5)，a”(-3，5) 2。 (3,3) 3.( 1) East (North), 350(350), North (East) Fill 1, 2,4. (1) A (1, 6), B (3,2), C( 1, 2) are in vertical brackets from bottom to top, and they are related to (the coordinates of symmetrical points on the Y axis are divided into 6 questions) 3. 2) (6.( 1) The highest temperatures on Monday, Wednesday, Thursday and Friday were recorded as (1, 2 1), (3,5), 2 (4,0/2) and (5,65438) respectively. Where (6, 18) indicates the highest temperature on Saturday, and the highest temperature on this day is 5. (1) omitted ②B6. (1) is the same as (2); The similar transition temperature is 18℃ 6.3 (2) (2) The highest temperature this week is Sunday; Affected by cold air, the temperature drops 1. (1) right, 3 (2) (-3, 3) (3) (x, 1) (0 ≤ x ≤ 3) 2. Slightly 7. At (2, 7). Then translate it down by 4 units to get point c6.2 (1) (3) translate point c to the left by 4 units, and then translate it down by 2 units to get point b 1. (2, -3), 3,22.c3. (1) Parallel (2) Parallel (4) Point (4) 1) 4. (1) A (1, 4), B (- 1, 2), C (1, 0) (2) Omit (3) in quadrants one, two, three and four respectively. C' coordinates are (-1, 0), (1, 0), (0, 1) 6. (1) Animal Training Hall, Sea Lion Hall and Bird Hall 6. ( 1) C (-2)。 Or do symmetrical transformation with the y axis as the symmetry axis. 7. The figure is omitted. The transformation to make the triangle after the transformation of point A still an isosceles right triangle is as follows: 6.2 (2) ① Move point A down by 4 units to the point (1,-2); 1.-4, (-8,0) ② Move point A to the right by 2 units, and then move it down by 4 units to point (3,0); 2. Establish a coordinate system with a straight line passing through point A and perpendicular to AB as the Y axis. A (0 0,0), B (5 5,0) and C (5 5,3) move point A to the right by 2 units to point (3,2); 5), d (0 0,5) ④ Move point A to the right 1 unit, and then move it down 1 unit to point (2,1); ⑤ Move point A to the right by 1 unit, and then move down by 3 units to (2,-1) point. Review question 5. (1) S = 360-70t (2) 220, which means the distance from the car to B is 220km6. (65438+).I (2) is (3) 16ω 1. (1) four (2) (0, 1) (3) 1 2. (2,5,2) 7.(65438+. The coordinate of any point in 7.2 (2) of the straight line L' obtained by upward translation by 3 units is expressed as (x, 1) 6. 2 7. What is the distance of light from point A to point B? 07 1.( 1) X is any real number (2)T≦- 1. 8.( 1) A (0，- 1)，B (0，2)，C (4，4)。 5(2)x = 1(2y+3)； -1 10.( 1) Sketch 3. (1) y = x+ 14, 4 < x < 14 (2) 20cm (2) The coordinates of each vertex of pattern II are (-) respectively. ② After △ ABC rotates 4 around the origin. (1) v = 2t, 0 ≤ t ≤ 20 (2) v = 16 180, mode Ⅱ 5. Get y = 1 2x2, 0 ≤ x ≤ 180. Sixty thousand
M/h 2.y，x； 1? 20 yuan /m3 1. -3,0; - 1,- 1; -3, 13. The constant is p, and the variables are m, Q2. ( 1) y = 1？ 2x is a linear function and a proportional function. 4. The constant is 10, 1 10, and the variable is n, H. 13 years old, which requires 9? 7 o'clock, 14 years old needs 9? 6 o'clock, 15 years old needs 9? 5 (2) y = 500-3x, which is a linear function, but not a proportional function. 5.( 1) t, t is the variable (2)t and w is the variable 6. F, x are variables and k is a constant 3. ( 1) q =-4t (2) 20。 06%)x； 5 153; Deposit 5000 yuan in the bank, and the sum of principal and interest is 5. (1) y = 0 after a fixed period of one year? 02t+50 (2) 80 yuan, 122 yuan 5 153 yuan 6. ( 1)t =-4.8h+24(2)9.6℃(3)6 km7。 (1) is (2) 23.88. 65.7 yuan; 129.4 yuan 2. (1) melon seed quality x (2) 14? 6 3.( 1)-4 (2)43 (3)44.( 1)4.9m； 122.5m (2) 4S58 7.3 (2) 3. (1) y = 600x+400 (2)1120 yuan 4. ( 1) Q = 95x+32(。 1.-3; 2-6 2.b5. (1) When 0≤x≤4, y = 1? 2x； When x > 4, y = 1? 6x- 1？ 6 (3.( 1) y = 2x+3, and x is an arbitrary real number (2) 1 (3) x 3 to be studied. 7.4 (2) Option 1, monthly waste residue treatment fee y 1=0 = 0? 05x+20, scheme 2, the monthly treatment fee of waste residue y2 = 0? 1x. 1。 C2.5 < s <113.y1< y2 The higher the treatment cost, the smaller the profit, so the scheme with lower treatment cost should be chosen. When the monthly output of the product is 4. (1) b (0, equal to 400 pieces, both schemes are acceptable. When it is more than 400 pieces, the option is 30, k = 98 cases 1 5. (1)100000 m3 (2)40 days 6. (1) Y = 320000-2000 x Review questions (2) The scheme is (0,7) p; 0.053 l/km； p=0？ 053s 10.62.At 3.77.5 ( 1) 2 1.y = 2？ 2x2。 Such as y =-x+ 1, etc. 4 . x≠35 . B6 . a7 .( 1)y =-52x(2)y = 2x+459 8 . y = 0.5x+ 15(0≤x){① 10。 ( 1)2(2)y = 2x+30(3) 10 0.9x+y = 10-0.8。 ② 1 1.(65438 gives y = 9.2-0.9x.③ 12. (1) 24 o'clock (2)12km (3)38 o'clock. Substituting ③ into ① gives X+9.2-0.9x > 10 and X > 8. Substitute x = 10 into ③ to get y = 0? 2. So the price of cookies is 1. Every box of 9 yuan.
Milk price per bag 1. 1 yuan; Or the price tag of biscuits is 2.d3.d4.b5.b6.b7.d 8.25 10 yuan per box, and that of milk is 0? 2 yuan 9.30 10. X >-5 1 1.40 12。 The median line on the bottom of isosceles triangle, the bisector of the vertex angle and the height on the bottom coincide; The median line on the hypotenuse of a triangle with a right angle of 27.7 is equal to half of the hypotenuse; Equilateral and angular; 28.( 1) 1500 yuan ∠ bad; The offset angle is equal, and the two straight lines are parallel (2) The printing cost is (2.2? 4+0.7? 6)? 2000 = 26,000 yuan, and the total cost of △ABC is 26,000+1500 = 27,500 yuan13.12 ≤ x < 214. The sketch is 15.5 16. (2.2? 4+0.7? 6) x+ 1500 ≤ isosceles triangle 60000, and x ≤ 4.5. ∴4≤x≤4.5； 18.10m19.d20.c21.c22.d23.c24.b2 If x≥5, it means 1000? (2.0? 4+0.6? 6) x+ 1500 ≤ 60000，x ≤ 5.04。 ∴ 5 ≤ x ≤ 5.04.25。 ( 1) a ( 1，г 3) (2)。