Distinguish between a survey and experimental design in quantitative research.

Does Red Increase Men’s Attraction to Women?

A study¹ examines the impact of the color red on how attractive men perceive women to be. In the study, men were randomly divided into two groups and were asked to rate the attractiveness of women on a scale of 1 (not at all attractive) to 9 (extremely attractive). Men in one group were shown pictures of women on a white background while the men in the other group were shown the same pictures of women on a red background. The results are shown in Table 1 and the data for both groups are reasonably symmetric with no outliers.

Table 1 Does red increase men’s attraction to women?

To determine the possible effect size of the red background over the white, find a 99% confidence interval for the difference in mean attractiveness rating μR-μW, where μR represents the mean rating with the red background and μW represents the mean rating with the white background.

Round your answers to two decimal places.

The 99% confidence interval is

calculate the probability of a person liking a dark-colored imported car over a light-colored imported car. Your answers are probabilities. Show your work.

The Dependent Variable (DV) is "Prefers Dark colored imported car." This measure is labeled"PrefDark" in the data
= 0 if preference is for a light colored car,
= 1 if preference is for a dark-colored car.

Here are the Independent Variables (IVs):
Age in years (no intervals – labeled "Age" in the data)

Gender (measure is labeled "Gender" in the data)
= 0 if male,
= 1 if female.

Education level (measure is labeled EducLevel in the data)
= 0 if completed high school only
= 1 if completed Associate's degree (Community College)
= 2 if completed Undergraduate degree (BA or BS)
= 3 if completed a Graduate degree

Income per year (in Euros, measure is labeled Income))

Consider, also, these coefficients for each measure (data point), calculated by running a Logit analysis on the data sample for the DV, PrefDark:

Coefficients and Constant
Age             0.101
Gender      0.34
EducLevel –5.1
Income      0.000142
Constant      3.22

Assume all coefficients and the constant are statistically significant (you can't ignore them).

Part 1:
Now consider this person, Respondent 1:
Age = 24
Gender = 1 (female)
EducLevel = 2 (Undergraduate degree)
Income/year = Euros 38000
What is the probability this person prefers a dark-colored imported car?

Part 2:
Additionally, consider this other person, Respondent 2:
54 year old male, with a graduate degree, earning Euros 58000 per year.
What is the probability this person prefers a dark-colored imported car?

Hint: Use the formula given in the video for calculating P(Y_i=y_i).

Show your work, please.

Part 3:
Which Respondent has a higher probability of preferring a dark-colored car?
This is quite straightforward if you have Parts 1 and 2 correct.

The process has an average of 40grams and a standard deviation of 2grams. With a confidence level of 90%, determine the average was reduced. Samples: 38, 39, 42, 40, 39, 41, 42, 40, 41, 42. Determine the 5 steps and the p-value of the hypothesis test.

solve the problem make sure to explain in words what you did with the problem and state your conclusions in terms of the problem.

Part I: Choose to do one of the following: 1) Test the claim that the mean Unit 3 Test scores of data set 7176 is greater than the mean Unit 3 Test scores of data set 7178 at the .05 significance level

Comparing Population Measures of Center and Dispersion

The HDL cholesterol (in mg/dL) of 10 males and 10 females were recorded for random samples of Americans as part of a National Center for Health Statistics survey.

1. What is the population for this survey?

2. Find the mode and the range for each data set:

           Female and Male

3. Find the 5 number summary for each data set.

For male and female:

Minimum, 1st Quartile, Median, 3rd Quartile, Maximum

4. Find the mean for each data set:

Female:_________ Male:_________

5. Find the standard deviation for each data set.

Female:_________Male:______ 6. Assuming the population standard deviations are σ = 15 mg/dL for females and σ = 12 mg/dL for males, construct the 95% confidence intervals for HDL cholesterol for each group using the data. Write a sentence that explains the correct interpretation of each confidence interval.

7. Use your confidence intervals to decide if it is possible that the population mean HDL

cholesterol is the same for females and males. Briefly explain the logic behind your decision.

For patients who have been given a diabetes test, blood-glucose readings are approximately normally distributed with mean 128 mg/dl and a standard deviation 10 mg/dl. Suppose that a sample of 4 patients will be selected and the sample mean blood-glucose level will be computed.

Enter answers rounded to three decimal places. According to the empirical rule, in 95 percent of samples the SAMPLE MEAN blood-glucose level will be between the lower-bound of _____ and the upper-bound of _____

Fat contents (in percentage) for 10 randomly selected hot dogs were given in the article "Sensory and Mechanical Assessment of the Quality of Frankfurters". Use the following data to construct a 90% confidence interval for the true mean fat percentage of hot dogs: (Give the answers to two decimal places.)
(  ,  )

create a histogram of with the data. One relatively easy way to do this is to divide the counts into 10 groups, say, each of length: (max length - min length)/10. Then compute the frequency of the data in each bin, and plot.

data: 143.344, 178.223, 165.373, 154.768, 155.56, 163.88, 178.99, 145.764, 174.974, 136.88, 173.84, 174.88, 197.091, 183.222, 138.233

please show work

1. A bowl of Halloween candy contains 20 KitKats and 35 Snickers. You are getting ready to grab 2 pieces of candy from the bowl without looking. Create a probability distribution where the random variable, x, represents the number of Snickers picked. (You can treat the probabilities as with replacement).

The distribution of actual weights of 8-oz chocolate bars produced by a certain machine is normal with mean 7.8 ounces and standard deviation 0.2 ounces. (a) What is the probability that the average weight of a bar in a random sample with three of these chocolate bars is between 7.64 and 7.96 ounces?

ANSWER:

(b) For a random sample of three of these chocolate bars, what is the level L such that there is a 4% chance that the average weight is less than L?

ANSWER:

Shelia's doctor is concerned that she may suffer from gestational diabetes (high blood glucose levels during pregnancy). There is variation both in the actual glucose level and in the blood test that measures the level. A patient is classified as having gestational diabetes if the glucose level is above 140 milligrams per deciliter one hour after a sugary drink is ingested. Shelia's measured glucose level one hour after ingesting the sugary drink varies according to the Normal distribution with mean 129 mg/dl and standard deviation 8 mg/dl. Let LL denote a patient's glucose level.

(a) If measurements are made on three different days, find the level LL such that there is probability only 0.05 that the mean glucose level of three test results falls above LL for Shelia's glucose level distribution. What is the value of LL?
ANSWER:

(b) If the mean result from the three tests is compared to the criterion 140 mg/dl, what is the probability that Shelia is diagnosed as having gestational diabetes?
ANSWER:

The scores of students on the SAT college entrance examinations at a certain high school had a normal distribution with mean μ=559.2μ=559.2 and standard deviation σ=28σ=28.

(a) What is the probability that a single student randomly chosen from all those taking the test scores 563 or higher?
ANSWER:  

For parts (b) through (d), consider a random sample of 25 students who took the test.

(b) What are the mean and standard deviation of the sample mean score x¯x¯, of 25 students?
The mean of the sampling distribution for x¯x¯ is:  
The standard deviation of the sampling distribution for x¯x¯ is:

(c) What z-score corresponds to the mean score x¯x¯ of 563?
ANSWER:

(d) What is the probability that the mean score x¯x¯ of these students is 563 or higher?
ANSWER:

The Graduate Record Examination (GRE) is a test required for admission to many US graduate schools. Student’s scores on the quantitative portion of the GRE follow a normal distribution with standard deviation of 8.8. Suppose a random sample of 10 students took the test, and their scores are given below:

152, 126, 146, 149, 152, 164, 139, 134, 145, 136  

1. Find a point estimate of the population mean. The point estimate for the population mean is 144.3.
2. Construct a 95% confidence interval for the true mean score for this population.
3. How many students should be surveyed to estimate the mean score within 3 points with 95% confidence?
4. How many students should be surveyed to estimate the mean score within 1 point with 95% confidence?
5. How many students should be surveyed to estimate the mean score within 0.5 points with 95% confidence?

PLEASE TYPE DONT WRITE THANK YOU!!

PLEASE SHOW ALL WORK IN EXCEL.

Use Bilingual sheet to answer this question.

A national survey of companies included a question that asked whether the company had at least one bilingual telephone operator. The sample results of 90 companies follow (Y denotes that the company does have at least one bilingual operator; N denotes that it does not).

The file Dataset_HW-3, sheet named Bilingual also contains the above survey results. Use this information to estimate with 80% confidence the proportion of the population that does have at least one bilingual operator.

[3 points]

Use Part-2 sheet to answer this question.

You are trying to estimate the average amount a family spends on food during a year. In the past the standard deviation of the amount a family has spent on food during a year has been approximately $1000. If you want to be 99% sure that you have estimated average family food expenditures within $50, how many families do you need to survey?

[2.5 points]

Use Part-3 sheet to answer this question.

You have been assigned to determine whether more people prefer Coke or Pepsi. Assume that roughly half the population prefers Coke and half prefers Pepsi. How large a sample do you need to take to ensure that you can estimate, with 95% confidence, the proportion of people preferring Coke within 3% of the actual value? [Hint: proportion est. = 0.5]

Records over the past year show that 1 out of 300 loans made by Mammon Bank have defaulted. Find the probability that 5or more out of 320 loans will default. Hint: Is it appropriate to use the Poisson approximation to the binomial distribution? (Round λ to 1 decimal place. Use 4 decimal places for your answer.)

Wild fruit flies have red eyes. A recessive mutation produces white-eyed individuals. A researcher wants to assess the proportion of heterozygous individuals. A heterozygous red-eyed fly can be identified through its off-spring. When crossed with a white-eyed fly it will have a mixed progeny.

A random sample of 100 red-eyed fruit flies was taken. Each was crossed with a white- eyed fly. Of the sample flies, 12 were shown to be heterozygous because they produced mixed progeny.

a) Check this data for the conditions necessary for the calculation of a large-sample confidence interval. Does it comply OR should you use the plus-four interval only?

b) Calculate the summary statistics from these data.

c) Determine a 95% confidence interval for the proportion of heterozygous flies.

d) Also use a test of significance at the 5% level to test the hypothesis that the proportion of heterozygous red-eyed flies is different to a proposed theoretical value of 17%?

e) Compare the answer from this test at the 5% level in d) to the conclusion you could make from the 95% confidence interval in c). Would you necessarily expect the same answer?