Tutors Answer Your Questions about Linear-regression (FREE)
Question 1168826: Researchers recorded facts about 77 breakfast cereals, including the calories and sugar content (in grams) of a serving. Based on the data, the following least squares regression equation can be used to predict the number of calories in a cereal by using the amount of sugar in the cereal.
predicted calories=89.5+2.5(sugar grams)
One popular brand of cereal contains 19 grams of sugar, and has a residual of +53 calories for one serving. What is the actual number of calories contained in one serving of this cereal?
Click here to see answer by CPhill(1959)   |
Question 1176480: 1. A manufacturer of basic commodities wants to know the relationship of advertising costs and sales. The data for a particular period on the two variables were recorded as follows:
Advertising costs (P1,000 )
20
40
30
50
25
30
40
35
45
20
25
40
Sales (P1,000)
385
400
489
580
410
475
510
500
525
360
420
480
Required:
a. Plot the data on a scatter diagram.
b. Find the equation of the regression line to predict sales from advertising costs.
c. Estimate the sales, if the advertising cost is P55,000.00.
Click here to see answer by CPhill(1959) |
Question 1176481: The relationship between the English and Mathematics score on a college entrance examination was conducted using the data below. Test the significance of r at 0.05 level.
Applicant No.
1
2
3
4
5
6
7
8
9
10
English score ( x )
86
55
75
93
89
67
60
52
83
86
Math score ( Y )
65
92
85
60
58
84
86
90
72
69
Click here to see answer by CPhill(1959) |
Question 1177110: Year 1970 1980 1985 1990 2000 2014 2016 2019
Prison Population 357,292 513,900 759,100 1,179,200 2,015,300 2,306,200 2,298,300 2,267,000
(a) What is the equation of the LSRL?
(b) When do we predict the prison population reached one and a half million?
(c) Interpret the slope of the regression line in the context of the problem.
(d) Is the line an appropriate model for these data? Explain. Your solution should reference the three factors that decide whether a model is an appropriate fit to data.
(e) How mass incarceration has disproportionately affected communities of color? Use statistics to justify your response.
Additional statistics are included below.
Additional Statistics:
Black men make up 6.5% of the US population and 40.2% of the US prison population.
The lifetime likelihood of imprisonment for White men is 1 in 17, for Black men is 1 in 3, and for Latino men is 1 in 6.
The lifetime likelihood of imprisonment for White women is 1 in 111, for Black women is 1 in 18, and for Latino women is 1 in 45.
In 2001, there were 878,400 African Americans in the prison population.
Click here to see answer by CPhill(1959) |
Question 1194165: Dear Sir/Madam,
manufacture wanted to know the effect of her spending in advertisement of on the sales, along with the other factors; ‘number of sales representatives’, ‘customer-satisfaction ratings’. For this research she has gathered the sales data in the following table, along
Write the Interpretation of Regression statistics-table, ANOVA- table.
Can you please post the output of the table or atleast
Coefficients Standard Error t Stat P-value
X1= Area,..... Y= Sales ...., X1 = Advertising spending ,....X2= no of sales person ,..... X3 = Customer satisfaction
….. Sales ….. Advertising ….. No of Sales Representative ….. customer-satisfaction,
Area A ….. 55,328 ….. 5,512 ….. 1 ….. 1
Area A1 ….. 56,251 ….. 8,337 ….. 1 ….. 1
Area A2 ….. 57,126 ….. 8,788 ….. 4 ….. 1
Area A3 ….. 58,739 ….. 8,828 ….. 5 ….. 1
Area A4 ….. 66,984 ….. 9,050 ….. 5 ….. 2
Area A5 ….. 70,676 ….. 10,150 ….. 7 ….. 2
Area A6 ….. 73,206 ….. 11,236 ….. 8 ….. 2
Area A7 ….. 80,571 ….. 12,538 ….. 8 ….. 3
Area A8 ….. 93,168 ….. 13,161 ….. 8 ….. 3
Area A9 ….. 99,432 ….. 13,448 ….. 9 ….. 4
Please note the customer Satisfaction : ( 1 is very poor , 5 is higly satisfactory)
Click here to see answer by proyaop(69) |
Question 1201133: The population of the Bothellville neighborhood has been growing steadily since 1985. In 1992, the population was 42300 people. In 2000, it was 57500 people. Find an equation in the form
y =mx +b where x is the number of years past 1985 and y is the population of Bothellville.
Click here to see answer by josgarithmetic(39615) |
Question 1196666: Because it is not practical to weigh bears in the field, researchers sought to develop a model to predict a bear's weight based on its length. Here are the results for a sample:
Total Length (cm) Weight (kg)
139.0 110
138.0 60
139.0 90
120.5 60
149.0 85
141.0 100
141.0 95
150.0 85
166.0 155
151.5 140
129.5 105
150.0 110
If the bear length was instead measured in inches (there are 0.3937 inches in 1 cm) and the weight was measured in pounds (there are 2.2 pounds in one kg), then the slope of the regression line would _______.
Group of answer choices
decrease by a factor of 0.179 (0.179 = 0.3937/2.2)
not change
increase by a factor of 0.179 (0.179 = 0.3737/2.2)
decrease by a factor of 5.588 (5.588 = 2.2/0.3937)
increase by a factor of 5.588 (5.588 = 2.2/0.3937)
Click here to see answer by math_tutor2020(3816) |
Question 1196666: Because it is not practical to weigh bears in the field, researchers sought to develop a model to predict a bear's weight based on its length. Here are the results for a sample:
Total Length (cm) Weight (kg)
139.0 110
138.0 60
139.0 90
120.5 60
149.0 85
141.0 100
141.0 95
150.0 85
166.0 155
151.5 140
129.5 105
150.0 110
If the bear length was instead measured in inches (there are 0.3937 inches in 1 cm) and the weight was measured in pounds (there are 2.2 pounds in one kg), then the slope of the regression line would _______.
Group of answer choices
decrease by a factor of 0.179 (0.179 = 0.3937/2.2)
not change
increase by a factor of 0.179 (0.179 = 0.3737/2.2)
decrease by a factor of 5.588 (5.588 = 2.2/0.3937)
increase by a factor of 5.588 (5.588 = 2.2/0.3937)
Click here to see answer by ewatrrr(24785)  |
Question 1196665: Because it is not practical to weigh bears in the field, researchers sought to develop a model to predict a bear's weight based on its length. Here are the results for a sample:
Total Length (cm) Weight (kg)
139.0 110
138.0 60
139.0 90
120.5 60
149.0 85
141.0 100
141.0 95
150.0 85
166.0 155
151.5 140
129.5 105
150.0 110
The residual associated with the bear whose length is 149.0 cm and weight is 85 kg is _______kg. (round your answer to three digits after the decimal)
Click here to see answer by math_tutor2020(3816) |
Question 1196551: A random sample of 8 applicants for a certain foreign job is selected. The number of years that these applicants have studied French in high school or university, X, and the mark which they obtained in a proficiency test in French, Y, are recorded. The following information is given: ∑X =32, ∑Y =528, ∑XY=2136, ∑X2 =130 and ∑Y2 =34872 Fitting a regression line, which of the following statements is incorrect?
a.
b₁ = 12
b.
Ŷ = 12+18Xi
c.
The predicted mark obtained if an applicant studied French for two years is 42.
d.
b₀ = 18
e.
Mean of X values = 4 Mean of Y values = 66
Click here to see answer by math_tutor2020(3816) |
Question 1194987: I need help with these math problems please thank you!
D. A football is kicked straight up into the air. Its height above the ground is approximated by the relation y=25x-5x^2, where y is the height of the ball in meters and x is the time in seconds. There are two times when the football is 27.5m in the air, on the way up and on the way down. Joe realizes that using the equation y=27.5, he can determine the two times the ball is 27.5 meters in the air. Algebraically or graphically determine these two times?
Click here to see answer by Solver92311(821)  |
Question 1190381: A data series is given for a periodic process:
0 1 2 3 4 5 6 7 8 9 10
1, 7 1, 7 2, 3 2, 9 3, 0 3, 5 4, 0 11, 0 9, 5 9, 7 9, 9
Please find a linear regression.
Is the use of a linear regression okay
Click here to see answer by math_tutor2020(3816) |
Question 1184417: A factory manufactures three types of golf balls: Eagle, Birdie, and Bogey. The daily production is 10,000 balls. The number of Eagle and Birdie balls combined equals the number of Bogey balls produced. If the factory makes three times more Birdie than Eagle balls, find the daily production of each type of ball.
Click here to see answer by greenestamps(13198)  |
Question 1174172: 6. The number of visitors to a cycle track and the number of drinks sold by a café at the
location are recorded in the table below.
Number of
visitors
32 45 39 43 58 84 65
Drinks sold 17 20 23 7 24 49 38
a. Identify the dependent and independent variable.
b. Calculate the correlation coefficient and comment on the value of r.
c. Calculate the regression line equation.
d. Using the equation, estimate the number of drinks that will be sold, if there are 50
visitors on a particular day.
Click here to see answer by ikleyn(52772)  |
Question 1051544: Scientists measured the annual forest loss (in square kilometers) in a country from 2000 to 2012. They found the regression line
forest loss = 7800 + (1028 � year since 2000)
for predicting forest loss in square kilometers from years since 2000.
What is the slope of this line?
If we measured forest loss in square meters per year, what would the slope be? Note that there are 106 square meters in a square kilometer.
If we measured forest loss in thousands of square kilometers per year, what would the slope be? (Enter your answer to three decimal places.)
Click here to see answer by jakub(1) |
Question 1165945: Three playing cards from an ordinary deck of 52 cards lie face down in a row. There
is a queen on the right of a jack. There is a queen on the left of a queen. There is a
diamond on the left of a heart. There is a diamond on the right of a diamond. What
are the three cards (name, suit, and position)?
Click here to see answer by greenestamps(13198) |
Question 1161446: Business. A small company has an assembly line that
produces three types of widgets. The basic widget is sold for
$10 per unit, the midprice widget for $12 per unit, and the
top-of-the-line widget for $15 per unit. The assembly line
has a daily capacity of producing 325 widgets that may be
sold for a total of $3825. Find the quantity of each type of
widget produced on a day when twice as many basic widgets
as top-of-the-line widgets are produced.
Click here to see answer by ikleyn(52772) |
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