Sally plays a game and wins with probability p. Every week, she plays until she wins two games, and then stops for the week. Sally calls it a "lucky week" if she manages to achieve her goal in 7 or less games.
a) If p = 0.2, what's the probability that Sally will have a "lucky week" next week?
b) What's the probability of exactly 3 "lucky weeks" in the next 5 weeks? What's the expected number of "lucky weeks" Sally will have in the next 10 weeks?
c) Let X be the number of games Sally plays in a week, and let q = 1 – p. Find the expectation E[X].
d) If Sally pays $1 to play each game, and gets $5 for each game she wins, what's her expected earning at the end of each week?
In: Statistics and Probability
Please show all work. A study was undertaken to see how accurate food labeling for calories on food that is considered reduced calorie. The group measured the amount of calories for each item of food and then found the percent difference between measured and labeled food, . The group also looked at food that was nationally advertised, regionally distributed, or locally prepared. The data is in table #11.3.5 ("Calories datafile," 2013). Do the data indicate that at least two of the mean percent differences between the three groups are different? Test at the 10% level.
Table #11.3.5: Percent Differences Between Measured and Labeled Food
National Advertised |
Regionally Distributed |
Locally Prepared |
2 |
41 |
15 |
-28 |
46 |
60 |
-6 |
2 |
250 |
8 |
25 |
145 |
6 |
39 |
6 |
-1 |
16.5 |
80 |
10 |
17 |
95 |
13 |
28 |
3 |
15 |
-3 |
|
-4 |
14 |
|
-4 |
34 |
|
-18 |
42 |
|
10 |
||
5 |
||
3 |
||
-7 |
||
3 |
||
-0.5 |
||
-10 |
||
6 |
In: Statistics and Probability
4. The weights of professional rugby players are normally distributed with mean weight 92 kilograms and standard deviation 12.8 kilograms.
(a) Find the probability that a randomly selected professional rugby player weighs less than 80 kilograms.
(b) Find the probability that a randomly selected professional rugby player weighs over 110 kilograms.
(c) Find the probability that a professional rugby player weighs between 80 and 100 kilograms.
(d) What weight separates the lightest 9% of professional rugby players from the rest?
(e) What weight separates the heaviest 2.5% of professional rugby players from the rest?
In: Statistics and Probability
An educator wants to determine whether early exposure to school will affect IQ. He enlists the aid of the parents of 12 pairs of preschool-age identical twins who agree to let their twins participate in his experiment. One member of each twin pair is enrolled in preschool for 2 years, while the other member of each pair remains at home. At the end of the 2 years, the IQs of all the children are measured.
Critical value = ________________ Test statistic = ________________
IQ
Twins at Twins at
Pair Preschool Home
1 120 114
2 121 118
3 127 103
4 117 112
5 115 117
6 120 106
7 130 115
8 119 113
9 121 109
10 120 112
11 117 116
12 121 104
Please help. Show all steps with answers and formulas used.
In: Statistics and Probability
In: Statistics and Probability
Create an excel workbook for the following questions. Answer these questions under your Solver work for each respective problem.
1. Devos Inc. is building a hotel. It will have 4 kinds of rooms: suites where customers can smoke, suites that are non-smoking, budget rooms where the customers can smoke, and budget rooms that are non-smoking. When we build the hotel, we need to plan for how many rooms of each type we should have. The following are requirements for the hotel:
Answer the following using your Solver answers:
In: Statistics and Probability
Find the lower z score that bounds the middle 65%? Round to the fourth.
In: Statistics and Probability
The population proportion is 0.36. What is the probability that a sample proportion will be within ±0.04 of the population proportion for each of the following sample sizes? (Round your answers to 4 decimal places.)
A)n=100
B)n=200
C)n=500
D)n=1000
What is the advantage of a larger sample size?
In: Statistics and Probability
In a recent survey concerning company sales and net earnings, 15 companies responded with the following information.
Company | Sales ($ thousands) |
Net Earnings ($ thousands) |
---|---|---|
Runners | 54.8 | 4.1 |
NorthCo | 24.0 | 0.8 |
JenStar | 42.6 | 2.2 |
Text Tech | 57.6 | 4.2 |
Capital Consultants | 56.7 | 3.6 |
Financial Services | 34.9 | 1.8 |
Cantu Excavating | 49.5 | 2.8 |
Pace Design | 25.7 | 1.0 |
CanTech Supply | 21.4 | 0.4 |
Second Time Around Clothing | 25.3 | 0.7 |
Echo Systems | 23.1 | -0.1 |
Antique Accents | 51.3 | 3.5 |
Spin Master Toys | 52.4 | 3.7 |
XYZ Co. | 37.1 | 1.3 |
Stiller Co. | 40.9 | 2.6 |
a) Using a statistical computing tool, find the
equation of the regression line.
For full marks your answer should be accurate to at least three
decimal places.
ŷ = ? + ?x
b) Use the regression line from part a to estimate
the net earnings for a company with sales of $54.8 thousand.
For full marks your answer should be accurate to at least one
decimal place.
Earnings: ?
c) | Given the regression equation from part a, which of the
following statements is most appropriate regarding company sales
and earnings?
|
In: Statistics and Probability
You are given the sample mean and the population standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. From a random sample of 35 business days, the mean closing price of a certain stock was $105.84. Assume the population standard deviation is $10.29.
In: Statistics and Probability
Use the SEM formula and show all work.
How satisfied are hotel managers with the computer systems their hotels use? A survey was sent to 400 managers in hotels of size 200 to 500 rooms in Chicago and Detroit. In all, 101 managers returned the survey. Two questions concerned their degree of satisfaction with the ease of use of their computer systems and with the level computer training they had received. The managers responded using a seven-point scale, with 1 meaning "not satisfied", and 4 meaning "moderately satisfied," and 7 meaning "very satisfied".
a. What do you think is the population for this study? What are the major shortcomings in the obtained data?
b. The mean response for satisfaction with ease of use was 5.396. Find the 95% confidence interval for the managers sampled. (Assume the sample SD = 1.75)
c. Provide an interpretation for your answer in part B.
d. For satisfaction with training, the mean response was 4.398. Assuming the sample SD is 1.75, find the 99% confidence interval for the managers sampled.
e. Provide an interpretation of your answer obtained for part D.
In: Statistics and Probability
A restaurant tried to increase business on Monday night, by featuring a special $1.00 dessert menu. The number of diners on each of 11 Mondays recorded while the special menu was in effect.
The data were
119 139 121 126 128 108 63 118 109 131 142
a. Find a 95% confidence interval the long-run number of diners.
b. Before the special menu, the restaurant average 105.2 diners per Monday night. Is it t reasonable to interpret the confidence interval from part “a” as indicating that the special menu did not increase the average number of diners?
In: Statistics and Probability
A random sample of 42 taxpayers claimed an average of $9,857 in medical expenses for the year. Assume the population standard deviation for these deductions was $2,409. Construct confidence intervals to estimate the average deduction for the population with the levels of significance shown below.
a)1%
b)2%
c)20%
In: Statistics and Probability
The manager of the main laboratory facility at Urban Health Center is interested in being able to predict the overhead costs each month for the lab. The manager believes that total overhead varies with the number of lab tests performed but that some costs remain the same each month regardless of the number of lab tests performed.
After running a regression analysis on the first seven months of the year, the manager of the main laboratory facility at Urban Health Center collects seven additional months of data. The number of tests performed and the total monthly overhead costs for the lab follow:
Number of Lab Tests |
Total Laboratory |
|
Month |
Performed |
Overhead |
August |
3,350 |
$23,500 |
September |
3,700 |
$27,550 |
October |
3,650 |
$24,500 |
November |
3,450 |
$26,400 |
December |
4,200 |
$28,500 |
January |
2,500 |
$22,800 |
February |
3,800 |
$25,350 |
Use Excel to do the following:
1. |
Run a regression analysis using data for August through February. |
2. |
Determine the lab's cost equation (use the output from the regression analysis you performed using Excel). |
3. |
Determine the R-square using the Excel output you obtain. What does the lab's R-square indicate? |
4. |
Predict the lab's total overhead costs for the month if 3,400 tests are preformed. |
Requirements 1 and 2. Use Excel to run a regression analysis using data for August through February and determine the lab's cost equation (use the output from the regression analysis you perform using Excel). (Enter all dollar amounts to two decimal places.)
y = $ |
x + $ |
In: Statistics and Probability
suppose average pizza delivery times are normally distributed with unknown population mean and population standard deviation of 6. A random sample of 28 pizza delivery restaurants is taken and has a sample mean of delivery time of 36 minutes. Show your work.
A. find critical value of 99% confidence level
b. sketch graph
c. what distribution should you use for this problem
d. calculate error bound
e. lower endpoint
upper endpoint
In: Statistics and Probability