Line of Best Fit Assignment and Quiz 100%

Which table shows a positive correlation?

b

The graph and table shows the relationship between y, the number of words Jean has typed for her essay and x, the number of minutes she has been typing on the computer. A 2-column table with 9 rows. The first column is labeled x with entries 5, 10, 15, 20, 25, 30, 35, 40, 45. The second column is labeled y with entries 271, 464, 820, 965, 1124, 1501, 1718, 2076, 2257. A graph shows the horizontal axis numbered 20 to 80 and the vertical axis numbered 1000 to 3000. A line increases from 0 to 80. According to the line of best fit, about how many words will Jean have typed when she completes 60 minutes of typing? 2,500 2,750 3,000 3,250

3,000

The table shows the temperature of an amount of water set on a stove to boil, recorded every half minute. According to the line of best fit, at what time will the temperature reach 100°C, the boiling point of water? 5 5.5 6 6.5

5

Titus works at a hotel. Part of his job is to keep the complimentary pitcher of water at least half full and always with ice. When he starts his shift, the water level shows 8 gallons, or 128 cups of water. As the shift progresses, he records the level of the water every 10 minutes. After 2 hours, he uses a regression calculator to compute an equation for the decrease in water. His equation is W -0.414t + 129.549, where t is the number of minutes and W is the level of water. According to the equation, after about how many minutes would the water level be less than or equal to 64 cups? 150 minutes 160 minutes 170 minutes 180 minutes

160 minutes

The graph shows the relationship between the number of ounces of cereal in a box and the price of the cereal. What is the correlation between the weight and price of a box of cereal? none positive negative constant

none

Melinda works at a cafe. Each day that she works, she records x, the total dollar amount of her customers' bills and then y, her total daily wages. The table shows her data for 2 weeks. According to the line of best fit, what is the minimum amount, to the nearest dollar, Melinda will earn for each day of work, even if she serves no customers? $18 $26 $36 $40

$26

Heather is training for a long-distance run. Her data points listed below represent the days of practice, x, and the number of miles run, y. (1, 2.5), (2, 4.2), (4, 5.6), (6, 7), (8, 8.1), (10, 11) Use the equation to interpolate the value and estimate the distance that she could have run on day 3. Round to the nearest tenth of a mile. day 3 ≈ miles

4.6

Mr. Palmer does an experiment to investigate the effects of distractions on studying and learning. He gives each participant a line with 10 words to memorize in 5 minutes. Some of the participants are interrupted during the 5 minutes with text messages from friends. The graph shows the number of words remembered after 5 minutes and the number of text messages sent to the participants as distractions. According to the line of best fit, about how many words would a person remember after being distracted by 7 text messages? 4 5 6 7

5

Which temperature values would an interpolation be limited to? less than 3 between 3 and 60 between 20 and 80 greater than 55

between 3 and 60

Rob is investigating the effects of font size on the number of words that fit on a page. He changes the font size on an essay and records the number of words on one page of the essay. The table shows his data. Which equation represents the approximate line of best fit for data, where x represents font size and y represents the number of words on one page? y = -55x + 407 y = -41x + 814 y = -38x + 922 y = -26x + 723

y = -26x + 723

John sells frozen fruit bars at a stand in a park during the summer months. He records the average weekly temperature and number of frozen fruit bars sold for 6 weeks. What type of correlation exists between the temperature and the number of fruit bars sold? positivenegativenone What is the real-world meaning of the slope of the line of best fit for the given scenario? There are approximately 1.42.24 more fruit bars sold for every 149 degree(s) the temperature rises.

positive 2.2 1

Which scenarios have a negative correlation? Check all that apply. the number of calories consumed and the amount of weight lost by a person the temperature outside and the number of pool guests the number of children assigned to a class and the number of desks the price of rice and the number of penguins at the South Pole the thickness of the ice on a lake and the likelihood of falling through the ice

the number of calories consumed and the amount of weight lost by a person the thickness of the ice on a lake and the likelihood of falling through the ice

Lydia runs an experiment to determine if a coin is fair by counting the number of times a coin lands heads up. The table shows her data. According to the line of best fit, about how many times would the coin land heads up in 100 flips? 48 50 51 53

53

Which table shows a negative correlation?

d

Teddy is preparing to sell some wooden blocks at a garage sale. Before pricing individual bags of blocks, he decides to determine the approximate number of blocks per pound by researching the weights of different sets of blocks. The graph shows his data. About how many blocks are there per pound? Round to the nearest block. 10 20 30 40

20

LaTasha was presented with the following data set and argued that there was no correlation between x and y. Is LaTasha correct? Use the regression equation to explain your reasoning.

LaTasha is correct. There is no correlation between x and y. The slope of the line of best fit is zero, which shows that there is no negative or positive correlation.

Kardal did a study to determine the correlation between men's heights, x, and their shoe sizes, y, and found the following data: (60, 8.5), (65, 10), (66, 12), (68, 11.5), (63, 9.5), (72, 12.5), (62, 8.5), (69, 12.5), (70, 11.5) Kardal used the line of best fit to predict that a man 80 inches tall would wear about a size 16 shoe. What can be concluded about this prediction? Check all that apply. The prediction is reasonable. The prediction is an interpolation. No data is given in the scatterplot for a height of 80 inches, but a shoe size can still be predicted. A prediction cannot be made for a man who is 80 inches tall. A man who is 80 inches tall will likely wear a size 12.5 shoe.

The prediction is reasonable. No data is given in the scatterplot for a height of 80 inches, but a shoe size can still be predicted.

Use the regression line for the data in the scatterplot to answer the question. On average, how many more goals will a player score for every additional hour of practice?

3/4 of a goal

Which scatterplot shows no correlation?

d