The following table gives data from a local school
district on children's ages (x) in years and reading levels(y). Age
in years X: 6, 7, 8, 9, 10, 11, 12, 14, 14, 15. Reading level Y:
1.3, 2.2, 3.7, 4.1, 4.9, 5.2, 6.0, 7.1, 8.5, 9.7.
Calculate the correlation coefficient r.
Calculate the coefficient of determination r2. Find the regression
coefficients and estimate the regression
equation.
Based on the estimated regression equation in (b), find the reading
level of a child who is 9.5 years.
In: Statistics and Probability
Isabelle Abiassi operates a popular summer camp for elementary school children. Projections for the current year are as follows:
| Sales revenue | $7,800,000 | |
| Operating income | $687,500 | |
| Average assets | $3,920,000 |
The camp’s weighted-average cost of capital is 11%, and Isabelle
requires that all new investments generate a return on investment
of at least 15%. The camp’s current tax rate is 25%.
At last week’s advisory board meeting, Isabelle told the board that
she had up to $50,000 to invest in new facilities at the camp and
asked them to recommend some projects. Today the board’s president
presented Isabelle with the following list of three potential
investments to improve the camp facilities.
| Playground | Swimming Pool | Gym | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Incremental operating income | $ 3,915 | $ 5,460 | $ 2,465 | ||||||
| Average total assets | 26,100 | 39,000 | 14,500 | ||||||
Calculate the return on investment, residual income, and economic value added for each of the three projects.
| Playground | Pool | Gym |
|---|
| Return on Investment | Enter percentages rounded to 0 decimal placesEnter percentages rounded to 0 decimal placesEnter percentages rounded to 0 decimal places | % | Enter percentages rounded to 0 decimal placesEnter percentages rounded to 0 decimal placesEnter percentages rounded to 0 decimal places | % | Enter percentages rounded to 0 decimal placesEnter percentages rounded to 0 decimal placesEnter percentages rounded to 0 decimal places | % | |||
|---|---|---|---|---|---|---|---|---|---|
| Residual Income | $Enter a dollar amount rounded to 0 decimal places Enter a dollar amount rounded to 0 decimal placesEnter a dollar amount rounded to 0 decimal places | $Enter a dollar amount rounded to 0 decimal places Enter a dollar amount rounded to 0 decimal placesEnter a dollar amount rounded to 0 decimal places | $Enter a dollar amount rounded to 0 decimal places Enter a dollar amount rounded to 0 decimal placesEnter a dollar amount rounded to 0 decimal places | ||||||
| Economic Value Added |
| Playground | Pool |
Gym |
|---|
In: Accounting
Professor Jennings claims that only 35% of the students at Flora
College work while attending school. Dean Renata thinks that the
professor has underestimated the number of students with part-time
or full-time jobs. A random sample of 82 students shows that 36
have jobs. Do the data indicate that more than 35% of the students
have jobs? Use a 5% level of significance.
What are we testing in this problem?
single proportionsingle mean
(a) What is the level of significance?
State the null and alternate hypotheses.
H0: p = 0.35; H1: p > 0.35H0: μ = 0.35; H1: μ < 0.35 H0: p = 0.35; H1: p < 0.35H0: p = 0.35; H1: p ≠ 0.35H0: μ = 0.35; H1: μ > 0.35H0: μ = 0.35; H1: μ ≠ 0.35
(b) What sampling distribution will you use? What assumptions are
you making?
The Student's t, since np > 5 and nq > 5.The standard normal, since np > 5 and nq > 5. The Student's t, since np < 5 and nq < 5.The standard normal, since np < 5 and nq < 5.
What is the value of the sample test statistic? (Round your answer
to two decimal places.)
(c) Find (or estimate) the P-value.
P-value > 0.2500.125 < P-value < 0.250 0.050 < P-value < 0.1250.025 < P-value < 0.0500.005 < P-value < 0.025P-value < 0.005
Sketch the sampling distribution and show the area corresponding to
the P-value.
(d) Based on your answers in parts (a) to (c), will you reject or
fail to reject the null hypothesis? Are the data statistically
significant at level α?
At the α = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant.At the α = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant. At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant.At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant.
(e) Interpret your conclusion in the context of the
application.
There is sufficient evidence at the 0.05 level to conclude that more than 35% of the students have jobs.There is insufficient evidence at the 0.05 level to conclude that more than 35% of the students have jobs.
In: Statistics and Probability
A survey conducted at Chicago Public Schools (CPS) involving high school students on whether they had participated in binged drinking during the past month. Binge drinking was defined as 5 or more drinks in a row on one or more of the past 30 days.
|
Number who identified as having participated in Binge Drinking. |
72 |
|
Total participants |
567 |
a. From the sample data is there evidence that the proportion of students who participate in binge drinking is greater than 10%? Write a null and alternative hypothesis and perform an appropriate significance test using
b. Construct a 90% Confidence Interval for the population proportion. Does it support the same conclusion as in part a? Explain.
In: Statistics and Probability
John was a high school teacher earning $ 80,000 per year. He quit his job to start his own business in pizza catering.In order to learn how to run the pizza catering business, John enrolled in a TAFE to acquire catering skills.John’s course was for 3 months. John had to pay $2,000 as tuition for the 3 months.
After the training, John withdrew $110,000 from his savings account. He had been earning 5 percent interest per year for this account. He also borrowed $50,000.00 from his friend whom he pays 6 percent interest per year. Further, to start the business John used his own premises. He was receiving $12,000from rent per year. Finally, to start the business John uses $50,000 he had been given by his father to go on holiday to USA.
John’s first year of business can be summarised as follows:
|
Item |
Amount $ |
|
Revenue- Pizza Section |
400,000 |
|
Revenue- Beverages Section |
190,000 |
|
2 Cashiers (wages per worker) |
55,000 |
|
Pizza ingredients |
50,000 |
|
Manager |
75,000 |
|
3 Pizza bakers (wages per baker) |
60,000 |
|
Equipment |
10,000 |
Based on your calculated accounting profit and economic profit, would you advise John to return to his teaching job? Show your work
In: Accounting
Professor Jennings claims that only 35% of the students at Flora
College work while attending school. Dean Renata thinks that the
professor has underestimated the number of students with part-time
or full-time jobs. A random sample of 83students shows that 38 have
jobs. Do the data indicate that more than 35% of the students have
jobs? Use a 5% level of significance.
What are we testing in this problem?
single mean
single proportion
(a) What is the level of significance?
State the null and alternate hypotheses.
H0: p = 0.35; H1: p > 0.35
H0: μ = 0.35; H1: μ < 0.35
H0: p = 0.35; H1: p < 0.35
H0: μ = 0.35; H1: μ > 0.35
H0: p = 0.35; H1: p ≠ 0.35
H0: μ = 0.35; H1: μ ≠ 0.35
(b) What sampling distribution will you use? What assumptions are
you making?
The standard normal, since np > 5 and nq > 5.
The Student's t, since np < 5 and nq < 5.
The Student's t, since np > 5 and nq > 5.
The standard normal, since np < 5 and nq < 5.
What is the value of the sample test statistic? (Round your answer
to two decimal places.)
(c) Find (or estimate) the P-value.
P-value > 0.250
0.125 < P-value < 0.250
0.050 < P-value < 0.125
0.025 < P-value < 0.050
0.005 < P-value < 0.025
P-value < 0.005
Sketch the sampling distribution and show the area corresponding to
the P-value.
(d) Based on your answers in parts (a) to (c), will you reject or
fail to reject the null hypothesis? Are the data statistically
significant at level α?
At the α = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant.
At the α = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant.
At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant.
At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant.
(e) Interpret your conclusion in the context of the
application.
There is sufficient evidence at the 0.05 level to conclude that more than 35% of the students have jobs.
There is insufficient evidence at the 0.05 level to conclude that more than 35% of the students have jobs.
In: Statistics and Probability
Physical activity generally declines when students leave high school and enroll in college. This suggests that college is an ideal setting to promote physical activity. One study examined the level of physical activity and other health-related behaviors in a sample of 1183 college students. Let's look at the data for physical activity and consumption of fruits. We categorize physical activity as low, moderate, or vigorous and fruit consumption as low, medium, or high. Here is the two-way table that summarizes the data.
| Physical activity | ||||
|---|---|---|---|---|
| Fruit consumption | Low | Moderate | Vigorous | Total |
| Low | 68 | 207 | 293 | 568 |
| Medium | 25 | 126 | 170 | 321 |
| High | 14 | 110 | 170 | 294 |
| Total | 107 | 443 | 633 | 1183 |
The first step in performing the significance test is to calculate the expected cell counts. Let's start with the cell for students with low fruit consumption and low physical activity. Use the following formula for expected cell counts.expected count =
| row total ✕ column total |
| n |
Using the formula, we need three quantities:
(1) the corresponding row total, 568, the number of students who
have low fruit consumption,
(2) the column total, , the number of students who have
low physical activity, and
(3) the total number of students, 1183.
The expected cell count is therefore the following.
|
|
||
| 1183 |
= 51.37Note that although any observed count of the number of
students must be a whole number, an expected count need not
be.
Calculations for the other eight cells in the 3 ✕ 3 table are
performed in the same way. With these nine expected counts we are
now ready to use the following formula for
the χ2
statistic.χ2 =
|
|||
The first term in the sum comes from the cell for students with low fruit consumption and low physical activity. The observed count is and the expected count is 51.37. Therefore, the contribution to the χ 2 statistic for this cell is the following.
|
||||
| 51.37 |
= 5.38When we add the terms for each of the nine cells, the result is the following. (Round your answer to two decimal places.)
χ 2 =
Because there are
r = 3
levels of fruit consumption and
c =
levels of physical activity, the degrees of freedom for this statistic are the following.df = (r − 1)(c − 1) = (3 − 1)
− 1
= Under the null hypothesis that fruit consumption and physical activity are independent, the test statistic χ 2 has a χ 2
distribution. To obtain the P-value, look at the
df =
row in Table F. The calculated value
χ 2 =
lies between the critical points for probabilities 0.005 and 0.01. The P-value is therefore between 0.005 and 0.01. (Software gives the value, rounded to four decimal places, as 0.0081.) There ---Select--- is is not strong evidence at α = 0.01 that there is a relationship between fruit consumption and physical activity.
In: Statistics and Probability
The data below provides College GPA, High School GPA, SAT total score, and a number of letters of reference. a.Generate a model for college GPA as a function of the other three variables? b.Is this model useful? Justify your conclusion. c.Are any of the variables not useful predictors? Why? CGPA HSGPA SAT REF 2.04 2.01 1070 5 2.56 3.4 1254 6 3.75 3.68 1466 6 1.1 1.54 706 4 3 3.32 1160 5 0.05 0.33 756 3 1.38 0.36 1058 2 1.5 1.97 1008 7 1.38 2.03 1104 4 4.01 2.05 1200 7 1.5 2.13 896 7 1.29 1.34 848 3 1.9 1.51 958 5 3.11 3.12 1246 6 1.92 2.14 1106 4 0.81 2.6 790 5 1.01 1.9 954 4 3.66 3.06 1500 6 2 1.6 1046 5 2.05 1.96 1054 4 2.6 1.96 1198 6 2.55 1.56 940 3 0.38 1.6 456 6 2.48 1.92 1150 7 2.74 3.09 636 6 1.77 0.78 744 5 1.61 2.12 644 5 0.99 1.85 842 3 1.62 1.78 852 5 2.03 1.03 1170 3 3.5 3.44 1034 10 3.18 2.42 1202 5 2.39 1.74 1018 5 1.48 1.89 1180 5 1.54 1.43 952 3 1.57 1.64 1038 4 2.46 2.69 1090 6 2.42 1.79 694 5 2.11 2.72 1096 6 2.04 2.15 1114 5 1.68 2.22 1256 6 1.64 1.55 1208 5 2.41 2.34 820 6 2.1 2.92 1222 4 1.4 2.1 1120 5 2.03 1.64 886 4 1.99 2.83 1126 7 2.24 1.76 1158 4 0.45 1.81 676 6 2.31 2.68 1214 7 2.41 2.55 1136 6 2.56 2.7 1264 6 2.5 1.66 1116 3 2.92 2.23 1292 4 2.35 2.01 604 5 2.82 1.24 854 6 1.8 1.95 814 6 1.29 1.73 778 3 1.68 1.08 800 2 3.44 3.46 1424 7 1.9 3.01 950 6 2.06 0.54 1056 3 3.3 3.2 956 8 1.8 1.5 1352 5 2 1.71 852 5 1.68 1.99 1168 5 1.94 2.76 970 6 0.97 1.56 776 4 1.12 1.78 854 6 1.31 1.32 1232 5 1.68 0.87 1140 6 3.09 1.75 1084 4 1.87 1.41 954 2 2 2.77 1000 4 2.39 1.78 1084 4 1.5 1.34 1058 4 1.82 1.52 816 5 1.8 2.97 1146 7 2.01 1.75 1000 6 1.88 1.64 856 4 1.64 1.8 798 4 2.42 3.37 1324 6 0.22 1.15 704 6 2.31 1.72 1222 5 0.95 2.27 948 6 1.99 2.85 1182 8 1.86 2.21 1000 6 1.79 1.94 910 6 3.02 4.25 1374 9 1.85 1.83 1014 6 1.98 2.75 1420 7 2.15 1.71 400 6 1.46 2.2 998 7 2.29 2.13 776 6 2.39 2.38 1134 7 1.8 1.64 772 4 2.64 1.87 1304 6 2.08 2.53 1212 4 0.7 1.78 818 6 0.89 1.2 864 2
In: Statistics and Probability
QUESTION
A reading program for fourth graders at Wiley Elementary School in Raleigh randomly selected 10 books from their recommended titles. The number of pages in each book is given below:
| 176 | 224 | 175 | 126 | 80 | 144 | 194 | 64 | 198 | 177 |
What is the standard deviation of the number of pages in these books? (round to two decimal places)
QUESTION
The table below lists tap water lead content in parts per billion for 71 residences in Flint, MI, in 2015.
| 0 | 104 | 10 | 6 | 5 | 0 | 3 | 0 | 13 | 4 | 2 | 2 |
| 8 | 6 | 2 | 1 | 1 | 0 | 2 | 7 | 3 | 5 | 5 | 0 |
| 0 | 5 | 5 | 42 | 22 | 8 | 20 | 6 | 2 | 5 | 3 | 2 |
| 3 | 2 | 3 | 4 | 21 | 7 | 3 | 42 | 0 | 7 | 0 | 6 |
| 28 | 18 | 1 | 2 | 3 | 1 | 5 | 0 | 3 | 10 | 2 | 3 |
| 2 | 5 | 2 | 3 | 0 | 3 | 9 | 11 | 0 | 0 | 0 |
Use Excel to calculate the following for this data set. Round all answers to two decimal places.
Mean:
Median:
Mode:
Range:
Standard Deviation:
QUESTION
The following data are the 2012-2013 salaries in thousands of dollars for 14 randomly selected Carolina Panthers football players:
| 465 | 490 | 490 | 490 | 540 | 540 | 540 |
| 700 | 770 | 1308 | 1500 | 2400 | 7750 | 8500 |
Use Excel to calculate the following. Round all answers to two decimal places if they are not whole numbers. If there is no mode, write NONE for the mode.
Mean:
Median:
Modes: (smaller) , larger
Range:
Standard Deviation:
QUESTION 8
The following data are the in-state tuition for a full time student at 15 randomly selected community colleges in North Carolina:
| 1294 | 1090 | 1241 | 1074 | 1336 |
| 1337 | 1452 | 1424 | 1344 | 1413 |
| 1379 | 1380 | 1419 | 1414 | 1382 |
Use Excel to calculate the following. Round to two decimal places for results that are not whole numbers. If there is no mode, write NONE for the mode.
Mean:
Median:
Mode:
Range:
Standard Deviation:
Please, show me your all works. Thanks.
In: Statistics and Probability
: Students from Elementary school were randomly separated into 4 groups and each group was taught a mathematical concept using a different teaching method. At the end of the teaching period, progress was measured by a unit test. The scores of shown below: (one child in group three was absent on the day the test was administered.)
(1) Construct an ANOVA table
(2) Do the data present significant evidence to indicate a difference in the average scores for the four teaching methods? Tabulated. (critical) F at α .05 = 3.29.
|
group |
|||
|
1 |
2 |
3 |
4 |
|
112 |
111 |
140 |
101 |
|
92 |
129 |
121 |
116 |
|
124 |
102 |
130 |
105 |
|
89 |
136 |
106 |
126 |
|
97 |
99 |
--- |
119 |
In: Statistics and Probability