Percent Increase and Decrease — Unit test Answers

The heights of the starting players on each of two basketball teams are shown in the table below.Heights of Starters on Team A and Team BTeam A70 in.72 in.75 in.68 in.70 in.Team B71 in.73 in.71 in.72 in.73 in.Jacob found that the mean height of Team A is 71 and the mean height of Team B is 72. He believes that because Team B has a greater mean, it also has a greater mean absolute deviation. Which explains Jacob’s error?

Julian and Nina are playing a game. Their scores for five games are shown in the table below.Julian’s and Nina’s ScoresJulian’s Scores4241465038Nina’s Scores4727453249Which statement comparing the medians to the ranges is true?

At Lawson Middle School, Mr. Hernandez asked 90 randomly selected students from each grade level for their favorite subject, and 28 chose social studies as their favorite. He used this data to draw the inference that out of the 250 middle school students, about 20% prefer social studies. Did he make a reasonable inference?

All 150 eighth grade students at a local middle school were asked how many hours they studied during the week. Each row of the table represents one sample from the population. Find the mean of each sample. Population DataRow 165304Row 245356Row 371453Row 442563Which row has the greatest mean?

Administrators surveyed students enrolled in a new school to choose the school mascot. The results are shown in the table below. What is the average number of students that chose grizzlies for both samples?Mascot SurveySample 1Sample 2Ducks12Ducks8Grizzlies24Grizzlies30Lions20Lions22Silverbacks16Silverbacks12

There are 20 classes at each of two middle schools. The number of students in each class at each school is shown in the dot plots below.Number of Students in Each Class at Poplar Middle SchoolNumber of Students in Each Class at Oak Middle SchoolWhat is the difference between the medians in the dot plots?

The wildflower commonly known as Ute Ladies’ Tresses is threatened. Some sample counts were taken of local populations of the flower as part of monitoring and protecting its population. These counts are displayed in the table below. What is the average number of plants at site 2 for both samples?Ute Ladies’ Tresses Mature Plant Count 20102012Site 18464Site 2112120

Vickie conducts a survey of home builders to determine the average cost of building a new home. She samples 10 home builders who are building in the town in which she lives. Under which conditions will her sample be a representative sample? Select two options.

The box plots show the average speeds, in miles per hour, for the race cars in two different races.Average Speeds of Cars in Race AAverage Speeds of Cars in Race BOne-half of cars travel at which speeds?

Harold took five different samples of thirty-five randomly selected students from the 520 students he surveyed. The means of the samples are shown below.SampleMeanSample 13.4Sample 23.2Sample 34.1Sample 44.6Sample 53.1The predicted mean of the population will fall between 3.1 and _______.

The student government at the local middle school surveyed students to help plan the end-of-year party. For the first sample, they surveyed every other person at sports practice after school. For the second sample, they surveyed every fifth person entering the cafeteria where all students eat. Which statement about the samples is true?End-of-Year Party SurveySample 1Sample 2Water Park21Water Park36Bowling/Arcade36Bowling/Arcade28Zoo16Zoo24Dance & Dinner27Dance & Dinner12

Nia recorded her science and math scores. The measures of center and variation for each score are shown in the table below.Measures of Center and Variationfor Nia’s Science and Math Scores ScienceMathMean6458Median6060Mode6262Range850Mean Absolute Deviation2.414.4Which inferences can be made when analyzing the data summary in the table? Select three choices.

These plots show the number of kilometers a group of students at Middleton Middle School and at Westwood Middle School travel to get to school each day. Number of Kilometers Middleton and Westwood Students Travel to SchoolThe shapes of which plots, if any, show an outlier?

Louden County Wildlife Conservancy counts butterflies each year. Data over the last three years regarding four types of butterflies are shown below. What is the average number of Variegated Fritillaries for all three samples?Louden County Butterfly Count200920102011Meadow Fritillary5Meadow Fritillary34Meadow Fritillary14Variegated Fritillary7Variegated Fritillary95Variegated Fritillary63Zebra Swallowtail33Zebra Swallowtail21Zebra Swallowtail10Eastern-Tailed Blue242Eastern-Tailed Blue168Eastern-Tailed Blue170

Out of a population of 700 students, 120 were asked by a random sampling to choose the green vegetable they would like to have served in the cafeteria. Their responses are shown in the table below.Cafeteria ChoicesGreen VegetableNumber of Studentspeas34green beans27broccoli23zucchini18brussels sprouts18Using proportional reasoning, about how many students out of the 700 would you expect to request broccoli to be served?