57 61 57 57 58 57 61 54 68 51 49 64 50 48 65 52 56 46 54 49 51 47 55 55 54 42 51 56 55 51 54 51 60 62 43 55 56 61 52 69 64 46 54 47
Create a frequency table using the data above
Use 7 classes
Show the relative and cumulative frequencies
List the class boundaries and class mid-points
What is the modal class?
In: Math
Answers are in bold under questions. I just need to know how to get them, so Please show work!!
A) If 25% of all vehicles at a certain emissions inspection failed the inspection. Assuming that successive vehicles pass or fail independently of one another. Calculate the following probabilities:
At least seven of the last 40 vehicles inspected failed.
0.9038
B) If 25% of all vehicles at a certain emissions inspection failed the inspection. Assuming that successive vehicles pass or fail independently of one another. Calculate the following probabilities:
In between 15 and 18 of the last 20 inspected passed
0.5929
C) If 25% of all vehicles at a certain emissions inspection failed the inspection. Assuming that successive vehicles pass or fail independently of one another. Calculate the following probabilities:
Given that less than 5 of the last 25 vehicles inspected failed, what is the probability that less than 3 of the 25 vehicles inspected failed?
0.1502
In: Math
During a command staff meeting a presentation is being made regarding a study recently completed by a consultant on crime suppression strategies. This study was commissioned by the Mayor who is under political pressure to reduce the crime rate in your community. The study revealed that crime rates are reduced by several factors, as indicated in a multiple regression statistical model. The consultant presented the following table which includes each factor and its beta coefficient. During the meeting the Captain sitting next to you turns to you and whispers, “I can’t make heads or tails of this statistics stuff. Which factor appears to have the most effect on reducing the crime rate?” Answer the Captain’s question. Assume each of the following beta coefficients are statistically significant. Factor A .534 Factor B -.345 Factor C .893 Factor D -602
In: Math
|
In: Math
In a few more weeks, you will be adding a new member to your family – a 10-week old golden retriever puppy! In previous litters, the average weight of 42 puppies at 10 weeks was 14.8 lbs with a standard deviation of 1.1 lbs.
Find the 90% confidence interval for the average 10-week weight for golden retriever puppies. Show/explain your work, and identify the following:
a. The estimated population mean and degrees of freedom
b. The assumptions you are making for this calculation
c. The critical value for the distribution
d. The margin of error
e. The 90% CI, stated as a complete sentence
In: Math
They main goal is to find either a Z score or T score for the
data below
What is the population mean and the sample mean for the elevations (in feet) of the trails below:
Mount Chocorua via Liberty Trail: 2,502 feet of elevation gain
Welch-Dickey Loop: 1,807 feet of elevation gain
Lonesome Lake Trail: 1,040 feet of elevation gain
Mount Willard: 985 feet of elevation gain
Red Hill Fire Tower: 1,350 feet of elevation gain
Pack Monadnock: 840 feet of elevation gain
Mount Cardigan’s Holt Trail: 1,800 feet of elevation gain
Mount Washington via Tuckerman Ravine: 4,238 feet of elevation gain
Presidential Traverse: 4,989 feet of elevation gain
Mount Moosilauke: 2,342 feet of elevation gain
The Carters: 3,305 feet of elevation gain
Mount Carrigain via Signal Ridge: 3,257 feet of elevation gain
Mount Flume + Mount Liberty Loop: 3,099 feet of elevation gain
Mount Isolation via glen boulder trail: 4,931 feet of elevation gain
Mount Monroe Trail: 2,572 feet of elevation gain
Maine
Hunt and Helon Taylor trail: 8,021 feet of elevation gain
Katahdin Loop Trail: 3,894 feet of elevation gain
Abol Trail: 3,950 feet of elevation gain
Hunt Trail: 4,169 feet of elevation gain
Mount Katahdin and Hamlin peak Trail: 4,438 feet of elevation gain
Baxter Peak Via Saddle Trail: 3,832 feet of elevation gain
Knife Edge Trail: 3,987 feet of elevation gain
Dudley Trail: 5,360 feet of elevation gain
Chimney pond Trail: 1,463 feet of elevation
Katahdin North Loop Trail: 4,061 feet of elevation gain
Doubletop Mountain Trail: 4,704 feet of elevation gain
Big Spencer Mountain Trail: 1,820 feet of elevation gain
North traveler Mountain Trail: 3,694 feet of elevation gain
Big Moose Mountain Trail: 1,843 feet of elevation gain
Cranberry Peak Trail: 2,070 feet of elevation gain
I was to choose 30 hiking trails (15 from New Hampshire and 15 from Maine) and record their elevations. My hypothesis for this is I believe that the mean is greater then or equal to 2,500ft. I'm having trouble figuring out my population mean and my sample mean. Also I need to find out my z score or t score and show a graph showing whether its left or right tailed or both.
In: Math
What role do variability and statistical methods play in controlling quality?
In: Math
(16.19) A class survey in a large class for first-year college students asked, "About how many hours do you study in a typical week?". The mean response of the 427 students was x¯¯¯ = 17 hours. Suppose that we know that the study time follows a Normal distribution with standard deviation 8 hours in the population of all first-year students at this university. What is the 99% confidence interval (±0.001) for the population mean? Confidence interval is from to hours.
In: Math
Month |
Nightly customers |
0 |
35 |
1 |
41 |
2 |
46 |
3 |
54 |
4 |
66 |
5 |
84 |
6 |
103 |
7 |
117 |
8 |
141 |
9 |
180 |
10 |
222 |
11 |
275 |
In: Math
Answer questions 33, 34, and 35 on separate sheets of paper and turn in with your scantron.
The ages of the Vice Presidents of the United States at the time of their death are listed below. Construct a frequency distribution to summarize the data. Use 6 classes. List the relative and cumulative frequencies. List the class boundaries and class midpoints. Use Excel to construct a histogram to display the data.
90 | 83 | 80 | 73 | 70 | 51 | 68 | 79 | 70 | 71 | 72 | |
74 | 67 | 54 | 81 | 66 | 62 | 63 | 68 | 57 | 66 | 96 | |
78 | 55 | 60 | 66 | 57 | 71 | 60 | 85 | 76 | 98 | 77 | |
88 | 78 | 81 | 64 | 66 | 77 | 70 |
Refer to the data set in question 33 above. Construct a stem and leaf plot to depict the ages of the vice-presidents at the time of their deaths.
Use EXCEL to construct a Pareto chart for the number of tons (in millions) of trash recycled per year by Americans based on an Environmental Protection Agency study.
Type | Amount |
Paper | 320 |
Iron/steel | 282 |
Aluminum | 268 |
Yard waste | 242 |
Glass | 196 |
Plastics | 42 |
In: Math
A regression analysis is conducted with 13 observations.
a. What is the df value for inference about the slope betaβ?
b. Which two t test statistic values would give a P-value of
0.05 for testing H0:β =0 against Ha: β ≠0?
c. Which t-score would you multiply the standard error by in order to find the margin of error for a
95%confidence interval for betaβ?
In: Math
In a test of the hypothesis that the population mean is smaller than 50, a random sample of 10 observations is selected from the population and has a mean of 47.0 and a standard deviation of 4.1. Assume this population is normal.
a) Set up the two hypotheses for this test. Make sure you write them properly.
b) Check the assumptions that need to hold to perform this hypothesis test.
c) Calculate the t-statistic associated with the sample.
d) Graphically interpret the p-value for this test, that is, i) draw a (nice) graph with a t-distribution (remember of the number of degrees of freedom) ii) locate on the graph the t-statistic you found in part (c) iii) mark the P-value on the graph
e) Calculate the P-value for this test.
f) Statistically interpret the P-value for this test.
g) Let the level of significance α = 2.5%. Using P-value, make a
conclusion for your test (write a complete sentence for full
credit).
h) Let the level of significance α = 2.5%. Find the related critical value tα.
i) What is the rejection region (RR) implied by α = 2.5% ?
j) Draw the RR on your graph on page 1, part (d).
k) Using the RR, make a conclusion for your test (write a complete sentence for full credit).
In: Math
Suppose x has a normal distribution with mean
μ = 28 and standard deviation σ = 4.
a) Describe the distribution of x values for sample size
n = 4. (Round σx to two
decimal places.)
μx | = |
σx | = |
b) Describe the distribution of x values for sample size
n = 16. (Round σx to two
decimal places.)
μx | = |
σx | = |
c) Describe the distribution of x values for sample size
n = 100. (Round σx to two
decimal places.)
μx | = |
σx | = |
d) How do the x distributions compare for the various
samples sizes?
I. The means are the same, but the standard deviations are decreasing with increasing sample size.
II. The standard deviations are the same, but the means are decreasing with increasing sample size.
III. The means and standard deviations are the same regardless of sample size.
VI. The means are the same, but the standard deviations are increasing with increasing sample size.
V. The standard deviations are the same, but the means are increasing with increasing sample size.
In: Math
In: Math
QUESTION 1
Which of the following scenarios are most suitable for the
chi-square test for difference in proportions?
Hint: There are 3 correct answers.
a. |
You want to know whether there is any difference between the average number of females and the average number of males who prefer working for a boss of the opposite gender as compared to a boss of the same gender. |
|
b. |
You are curious to find out if there is any difference in the average incomes among the U.S., Canada and the U.K. |
|
c. |
You wonder whether there is any difference in the proportions of smokers between female high school students and male high school students. |
|
d. |
You are interested in finding out whether the proportions of students who agree that NAU should increase its tuition further are the same across freshmen, sophomores, juniors and seniors. |
|
e. |
You are interest in finding out whether the percentages of PCs that break down within the first month are the same across five different manufacturers. |
|
f. |
You want to know whether the percentage of republicans who favor a tax cut is higher than the percentage among democrats. |
QUESTION 2
Which of the following scenarios are most suitable for the
chi-square test for independence?
Hint: There are 2 correct answers.
a. |
You want to know if there is any connection between a person’s hair color and eye color. |
|
b. |
You want to know whether there is any difference between the average number of females and the average number of males who prefer working for a boss of the opposite gender as compared to a boss of the same gender. |
|
c. |
You are curious to find out if the variations of smokers are the same across freshmen, sophomores, juniors and seniors at NAU. |
|
d. |
You wonder whether political party affiliation is related to gender. |
|
e. |
You are curious to find out if there is any difference in the average incomes among the U.S., Canada and the U.K. |
|
f. |
You want to know whether median income of republicans are higher than the median income of democrats. |
QUESTION 3
Which of the following scenarios are most suitable for the Z
test for difference in two proportions?
Hint: There are 2 correct answers.
a. |
You are interested in finding out whether the proportions of students who agree that NAU should increase its tuition further are the same across freshmen, sophomores, juniors and seniors. |
|
b. |
You are interest in finding out whether the percentages of PCs that break down within the first month are the same across five different manufacturers. |
|
c. |
You wonder whether political party affiliation is related to gender. |
|
d. |
You want to know if there is any connection between a person’s hair color and eye color. |
|
e. |
You wonder whether there is any difference in the proportions of smokers between female high school students and male high school students. |
|
f. |
You want to know whether the percentage of republicans who favor a tax cut is higher than the percentage among democrats. |
|
g. |
You are curious to find out if there is any difference in the average incomes among the U.S., Canada and the U.K. |
|
h. |
You want to know whether there is any difference between the average number of females and the average number of males who prefer working for a boss of the opposite gender as compared to a boss of the same gender. |
QUESTION 4
When should the Marascuilo procedure be used?
a. |
To find out if there is any difference in any pair of population proportions when one fails to reject the chi-square test for two proportions. |
|
b. |
To find out if there is any difference in any pair of population proportions once the chi-square test for more than two proportions is rejected. |
|
c. |
To find out if there is any difference in any pair of population porportions when one fails to reject the chi-square test for more than two proportions. |
|
d. |
To find out if there is any difference in any pair of population proportions once the chi-square test for two proportions is rejected. |
QUESTION 5
The computation and operation procedure of the chi-square test
for independence is exactly the same as those of which of the
following?
One correct answer.
a. |
one-way ANOVA F test |
|
b. |
Z test for difference in two proportions |
|
c. |
Tukey-Kramer procedure |
|
d. |
Chi-square test for difference in more than two proportions |
|
e. |
Marascuilo procedure |
|
f. |
Z test for difference in two means |
In: Math