A scooter company wants to determine the average amount of time it takes an adult to assemble an “easy to assemble” scooter. A sample of 49 times yielded an average time of 18.15 minutes. Assume that the assembly times are normally distributed and the population has a standard deviation of 5.39 minutes.

a) Give a point estimate for the population mean that the sample of data is taken from.

b) Find the 96% confidence interval for the mean assembly time.

1. A sample of HR managers were selected to examine whether they expect job seekers of different races (Black vs. White) to negotiate salary offers. In the experiment, each participant was randomly assigned to view one of two versions of a fictitious job seeker’s resume. Resumes in the two conditions contained identical names, background, and job history information; the job seeker’s race was manipulated through the pictures shown at the top of the resume (Black male or White male). Each participant was asked to rate “Do you think this job seeker is to negotiate his salary offer?” (Responses were measured on a Yes-No format, 1 = Yes, 0 = No).

1. Two independent sample mean comparison
2. Two-way ANOVA
3. Independence Chi-square test
4. Correlation

1. In the recent employee engagement survey, a sample of customer service employees were asked to report how often customers generally engaged in misbehaviors toward them in the past three months (measured on a 7-point Likert-type scale, 1 = never, 7 = always). The company wants to know whether different types of service employees (1 = full-time; 2 = part-time) received customer misbehaviors to the same extent.

1. Two paired sample mean comparison
2. Two-way ANOVA
3. Two Independent sample mean comparison
4. Independence Chi-square test

1. A manufacturing company wants to explore whether there are regional differences in individual employee turnover intention. In a recent employee attitudinal survey, the company asked 120 employees at three different plants of the company (1 = Ohio, 2 = Michigan, 3 = Pennsylvania) about the extent to which they plan to leave the company in the next 6 months (measured on a 5-point Likert-type scale, 1 = very unlikely, 5 = very likely).

1. Two independent sample mean comparison
2. One-way ANOVA
3. Two-way ANOVA
4. Independence Chi-square test

1. A university identified 50 faculty members who taught both online courses and traditional classroom courses in the Fall Semester 2018 and collected their Student Evaluation of Instruction (SEI) scores for the online courses and the traditional courses. The university wanted to use this dataset to evaluate whether instructors receive the same level of student evaluations when they teach online courses and traditional courses in classroom.
   

1. Two independent sample mean comparison
2. One-way ANOVA
3. Two paired sample mean comparison
4. Independence Chi-square test

1. A research team wants to examine whether switching jobs can increase pay for both male and female faculty. They collected a sample of 200 assistant professors in Management who graduated in 2015 and asked them to report their salary (in dollar), their gender (1 = male, 2 = female) and whether they had changed jobs since graduation (1 = Yes, 0 = No).  

1. Simple regression
2. Multiple regression
3. Two-way ANOVA
4. Two independent sample mean comparison

Test if a person’s political affiliation and their opinion on a tax reform bill
are dependent at a 10% level of significance.

Favor Indifferent Opposed
Democrat 79 129 98
Republican 73 69 65

The data in the table represent the number of licensed drivers in various age groups and the number of fatal accidents within the age group by gender. Complete parts​ (a) to​ (c) below.

Age   Number_of_Male_Licensed_Drivers_(000s), Number_of_Fatal_Crashes, Number_of_Female_Licensed_Drivers0000s), Number_of_Fatal_Crashes
<_16   12   227   12   77
16-20   6424   5180   6139   2113
21-24   6936   5016   6816   1550
25-34   18068   8565   17664   2780
35-44   20406   7990   20061   2742
45-54   19898   7126   19984   2285
55-64   14363   4527   14441   1514
65-74   8194   2274   8398   938
>_74   4803   2022   5375   957

(a) Find the​ least-squares regression line for males treating the number of licensed drivers as the explanatory​ variable, x, and the number of fatal​ crashes, y, as the response variable. Repeat this procedure for females.

(b) Interpret the slope of the​ least-squares regression line for each​ gender, if appropriate. How might an insurance company use this​ information?

(c) Was the number of fatal accidents for 16 to 20 year old males above or below​average? Was the number of fatal accidents for 21 to 24 year old males above or below​average? Was the number of fatal accidents for males greater than 74 years old above or below​ average? How might an insurance company use this​ information? Does the same relationship hold for​ females?

Consider a normal population with μ = 40 and σ = 4.2. Calculate the z-score for an x of 49 from a sample of size 15. (Give your answer correct to two decimal places

The mass of an object is normally distributed with a mean of μ = 3480 grams and a standard deviation of σ = 550 grams. Find the 28th percentile in this population.

a. 3161 grams

b. 2834 grams

c. 3050 grams

d. 2824 grams

Part B.) If five objects from the population are randomly selected, what is the probability the mean mass among them is less than 3229 grams?

a.) 0.1539

b.) 0.4020

c.) 0.546

d.) 0.0250

THIS QUESTION WAS ANSWERED BEFORE BUT A-D. PLEASE ANSWER SECTION E.

There is no mass transit in Cedar Grove, so Letecia’s goats are fascinated with buses and trains now that they live in SoCal. In fact, they spend anywhere between 30 and 150 minutes each day on some form of mass transit or other, and no length of time is any more likely than any other.
a. Draw a graph of the distribution of the amount of time that any of Letecia’s goats spends on mass transit in a day.
b. What is the probability that one of Letecia’s goats spends more than two hours on mass transit in a day?
c. What is the probability that one of Letecia’s goats spends exactly one hour on mass transit in a day?
d. What is the amount of time one of Letecia’s goats is expected to spend on mass transit in a day? What is the standard deviation?
e. Supposing that the amount of time a goat spends on mass transit each day is independent. What would be the probability that a goat would spend more than 23 complete days on mass transit over the course of a year?

Male sample size: 30

Female sample size: 62

Use the following data

a) Which measure, the mean or the median, do you think better represents a typical number of deaths from a hurricane? Why?

b) Based upon the mean and median, do you think that the Female named hurricanes are more deadly? Why? Or why not?

c) Find a 95% confidence interval for the number of death by both female and male named hurricanes.

d) Find a 99% confidence interval for the number of death by both female and male named hurricanes.

e) Compare the CIs of 95% and 99% levels.

PLEASE DO OUT ALL WORK NO COMPUTER PROGRAMS

A normally distributed population has a mean of 65 and a standard deviation of 24. Sample averages from samples of size 19 are collected. What would be the lower end of the centered interval that contains 90% of all possible sample averages?

I know how to do a most of this, but I am confused on how I find the Z variable. Thanks!

if you're constructing a 95% confidence interval for the MEAN of some population, and you collect a sample of size 100 that has a sample mean of x-bar=30 with a population standard deviation of _=20, then how much would the margin of error of the confidence interval be? use 3 decimal places of accuracy

A sample of freshmen takes a reading comprehension test and their scores are summarized below. If the mean for the general population on this test is m = 12, can you conclude that this sample is significantly different from the population. Test with a = .05.
Sample Scores: 16, 8, 8, 6, 9, 11, 13, 9, 10

A. Find M=

B.Find SS=

C.Find standard error =

D.Find t =

E. Choose one:

Reject H₀ =1

Fail to Reject H₀ =2

What is the purpose of the Bonferroni correction (and other similar ‘corrections’)? How is it applied and what problem does it fix? What is the cost of using these corrections?

An engineer wants to determine how the weight of a​ car, x, affects gas​ mileage, y. The following data represent the weights of various cars and their miles per gallon.

Car   Weight (pounds), x   Miles per Gallon, y
A   2695   26.7
B   2975   23.6
C   3260   24.9
D   3760   23.1
E   4225   20.4

a) Find the​ least-squares regression line treating weight as the explanatory variable and miles per gallon as the response variable.

Write the equation for the​ least-squares regression line.

Modifying Above y with carety =__x+__

(b) Interpret the slope and​ intercept, if appropriate.

(c) Predict the miles per gallon of car B and compute the residual. Is the miles per gallon of this car above average or below average for cars of this​ weight?

D) Draw the​ least-squares regression line on the scatter diagram of the data and label the residual.

In the Focus Problem at the beginning of this chapter, a study was described comparing the hatch ratios of wood duck nesting boxes. Group I nesting boxes were well separated from each other and well hidden by available brush. There were a total of 465 eggs in group I boxes, of which a field count showed about 274 hatched. Group II nesting boxes were placed in highly visible locations and grouped closely together. There were a total of 782 eggs in group II boxes, of which a field count showed about 260 hatched.

(a) Find a point estimate p̂₁ for p₁, the proportion of eggs that hatch in group I nest box placements. (Round your answer to three decimal places.)
p̂₁ =

Find a 99% confidence interval for p₁. (Round your answers to three decimal places.)

(b) Find a point estimate p̂₂ for p₂, the proportion of eggs that hatch in group II nest box placements. (Round your answer to three decimal places.)
p̂₂ =

Find a 99% confidence interval for p₂. (Round your answers to three decimal places.)

(c) Find a 99% confidence interval for p₁ − p₂. (Round your answers to three decimal places.)

A study was conducted to determine the proportion of people who dream in black and white instead of color. Among 293 people over the age of​ 55, 69 dream in black and​ white, and among 305 people under the age of​ 25,18 dream in black and white. Use a 0.05 significance level to test the claim that the proportion of people over 55 who dream in black and white is greater than the proportion for those under 25. Complete parts​ (a) through​ (b)

a. Consider the first sample to be the sample of occupants not wearing seat belts and the second sample to be the sample of occupants wearing seat belts. What are the null and alternative hypotheses for the hypothesis​ test?

Identify the test statistic.

Identify the​ P-value.

b. Test the claim by constructing an appropriate confidence interval.