92% Scatter plots Unit Test

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. 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

C.

Which r-value represents the weakest correlation? -0.75 -0.27 0.11 0.54

C.

Which table of values represents the residual plot?

A. (1,2,1.94)(2,3.5,3.41)(3,4.7,4.88)(4,6.2,6.35)(5,8,7.82)

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

A line of best fit is f(x) ≈ −0.86x + 13.5 for the set of points in the table. Using the equation for the line of best fit, what is a good approximation for the value of the function, f(x), when x = 18? −5 −2 3 12

-2

Kiley gathered the data in the table. She found the approximate line of best fit to be y = 1.6x - 4. What is the residual value when x = 3? -1.8 -0.2 0.2 1.8

0.2

Points and their residual values are shown in the table. Which residual value is the farthest from the line of best fit?

0.7

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. blocks per pound

20 blocks per pound

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 if he or she is distracted by 7 text messages? words

5 words

Find the residual values, and use the graphing calculator tool to make a residual plot. Does the residual plot show that the line of best fit is appropriate for the data? No, the points are in a curved pattern. No, the points are evenly distributed about the x-axis. Yes, the points are in a linear pattern. Yes, the points have no pattern.

A.

Scientists studied a deer population for 10 years. They generated the function f(x) = 248(1.15)x to approximate the number of deer in the population x years after beginning the study. About how many deer are in the population 3 years after beginning the study? 251 377 856 1,003

A.

The graph shows the data points in the table and the exponential regression model associated with the data. Based on the graph of the regression model, which is true? The number of weeds is decreasing by a multiplicative rate. The number of weeds is increasing by a multiplicative rate. The number of weeds is decreasing by an additive rate. The number of weeds is increasing by an additive rate.

A.

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

A.

The table shows the estimated number of bees, y, in a hive x days after a pesticide is released near the hive. Which function best models the data? y = 9,958(0.972)x y = 0.972(9,958)x y = 9,219x- 150 y = -150x + 9,219

A.

Georgianna wants to use the linear model associated with the data in the table to make a prediction. Which range of time values describes the entire interval over which she would be interpolating? 0 to 5 minutes 0 to 18 minutes 0 to 30 minutes 18 to 30 minutes

C.

The function f(t) = 349.2(0.98)t models the relationship between t, the time an oven spends cooling and the temperature of the oven. For which temperature will the model most accurately predict the time spent cooling? 0 100 300 400

C.

Which r-value represents the most moderate correlation? -0.92 -0.18 0.56 0.83

C.

Which relationships would most likely be causal? Check all that apply. a negative correlation between the temperature and the amount of snow still on the ground a negative correlation between the number of digital photos uploaded to a website and the amount of storage space that is left a positive correlation between the length of the side of a pool and its depth a positive correlation between the height of a woman and the height of her brother a negative correlation between the volume of water in a pot and the amount of time that the water takes to boil

a negative correlation between the temperature and the amount of snow still on the ground a negative correlation between the number of digital photos uploaded to a website and the amount of storage space that is left

Juan analyzes the amount of radioactive material remaining in a medical waste container over time. He writes the function f(x) = 10(0.98)x to represent the amount of radioactive material that will remain after x hours in the container. Rounded to the nearest tenth, how much radioactive material will remain after 10 hours? units

8.2 units

What does a residual value of -0.8 mean in reference to the line of best fit? The given point is 0.8 units above the line of best fit. The given point is 0.8 units below the line of best fit. The line of best fit is not appropriate to the data. The line of best fit has a slope of 0.8.

B.

Consider the table showing the given, predicted and residual values for a data set. Which point would be on the residual plot of the data? (1, -2.2) (2, 1.5) (3, 3.7) (4, 0.1)

D.

Janna is making a prediction of the frequency of a key that is 12 keys from middle C. Which best describes her prediction? interpolation, because a key that is 12 keys from middle C is within the data set interpolation, because a key that is 12 keys from middle C is outside the data set extrapolation, because a key that is 12 keys from middle C is within the data set extrapolation, because a key that is 12 keys from middle C is outside the data set

D.

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

D.

The table shows the shipping costs for items of different values. Which best describes the strength of the model? a weak positive correlation a strong positive correlation a weak negative correlation a strong negative correlation

D.

Which table shows a negative correlation?

D. (2,4) (5,2) ect...