You were interested in how long the average psychology major at your college studies per night, so you asked 10 psychology majors to tell you the amount time they study.

You were given the following 'study times': 2, 1.5, 3, 2, 3.5, 1,   0.5, 3,   2, 4.

What is the appropriate distribution for finding a confidence interval?

Select the correct answer and enter the appropriate letter.

a     Uniform distribution

b     Normal distribution

c     t distribution

d     Chi Square distribution

______

What is the degrees of freedom (df)?

If the question is inappropriate for the distribution selected, enter the number 0 or Na.

______

What is the mean and standard deviation of the sample?

I recommend using Excel or a Scientific calculator for determining the mean and standard deviation of the data set. .

Enter the mean and standard deviation rounded to two decimal places in the order requested.

___________

Find a 90% confidence interval for the population mean.

Use the mean and standard deviation rounded to 2 decimal places in your calculations.

Enter the lower number for the confidence interval first and the upper number for the confidence next.

Enter each number rounded to 2 decimal places.

2.

A person claims to be able to predict the outcome of flipping a coin. Their claim will be accepted if they can predict the outcomes of flipping a coin on average with a higher percentage that would occur by change, guessing (50%). Upon performing the experiment, the person is correct 18 out of 25 times. Answer the following questions based upon the above experiment.

What is the point estimate for the proportion of times the person predicted the coin flips correctly?
Enter answer as a fraction or a 2 place decimal with a zero to the left of the decimal point.  Do not enter your answer in percent.

______

What is the sample size being used for calculating a confidence interval for the proportion of heads demonstrated base upon the reported data? Enter answer as an integer.

______

Compute a 95% confidence interval for the proportion of times the person predicted the coin flips correctly. Enter the lower number and the upper number for the confidence interval with the lower number first. Enter answer as a decimal rounded to 3 decimal places with a zero to the left of the decimal point. Do not enter your answer in percent.

____________

What conclusion can you draw from the confidence interval about the ability of the person to predict the outcome of a coin flip?

Select the correct answer and enter the letter that is associated with that answer.

a Based upon the data, the calculated conference interval supports the claim that the person flipping the coins can predict the outcomes.
b Based upon the data, the calculated conference interval does not support the claim that the person flipping the coins can predict the outcomes.
c     There is insufficient information to draw any conclusion from the experimental results

______

What number must the lower number in the confidence interval exceed in order for the confidence interval to support the claim of being able to predict the outcome of flipping a coin?

Enter answer to 1 decimal place with a 0 to the left of the decimal point.

______

1.In a recent sample of 84 used car sales costs, the sample mean was $6,425 with a sample standard deviation of $3,156.

Assume the underlying distribution is approximately normal.

Which distribution should you use for for determining a confidence interval for estimating the population mean for used car sales costs?

What is the number of degrees of freedom (df) for this problem.

Answer this question by:

Select the correct distribution and enter the appropriate letter.

Enter the degrees of freedom (df) for this problem. If this is an inappropriate question for the distribution being used enter the number 0

a   Normal Distribution

b     t Distribution

c     Uniform

d     Chi Sq distribution

Enter the answers for the 2 questions being asked in the same order in which they were asked.

________________

Define the random variable X by selecting the appropriate letter below.

a     An individual data item randomly selected from the population, some times referred to as the parent population.

b     The average of n individual data item randomly selected from the parent population. In this question n is 84.

Define the random variable X ¯ (Xbar) by selecting the appropriate letter below.

c     An individual data item randomly selected from the population, sometimes referred to as the parent population.

d     The average of n individual data item randomly selected from the parent population. In this question n is 84.

Enter your answers in the order in which the questions were asked.

________________

Construct a 95% confidence interval for the population mean time wasted.

Enter your answers rounded to 0 decimal places (Enter answer as an integer).

In the two answer locations provided enter the lower bound of the confidence interval first followed by the upper bound.

________________

What is meant by the term “95% confident” when constructing a confidence interval for a mean?

a.    If we took repeated samples, approximately 95% of the samples would produce the same confidence interval.

b     If we took repeated samples, approximately 95% of the confidence intervals calculated from those samples would contain the sample mean.

c     If we took repeated samples, the sample mean would equal the population mean in approximately 95% of the samples

d     If we took repeated samples, approximately 95% of the confidence intervals calculated from those samples would contain the true value of the population mean..

Enter the correct answer by selecting the appropriate letter

2.

The owner of the Britten's Egg Farm wants to estimate the mean number of eggs produced per chicken.  A representative random sample of 25 chickens show they produce an average of 20 eggs per month with a sample standard deviation (s) of 2 eggs per month. The distribution is known to be symmetrical and is close enough to normal to be treated as a normal distribution.

Answer the following questions related to the above paragraph and calculate a 90% confidence interval for the mean number of eggs produced per chicken on the Britten's Egg Farm.

a     What is the point estimate of the mean number of eggs produced per chicken?
       Enter answer with 0 decimal places (integer).

______

b     What is the appropriate distribution for calculating a 90% confidence interval?

a     Uniform distribution

b     Normal distribution

c     t distribution

d     Chi Square distribution

Answer this question by entering the appropriate letter.

______

c     The degrees of freedom (df) for this problem is?
       Enter Na or 0 for the df if the appropriate distribution does not required a df.

______

e     The 90% conference interval for the mean number eggs produced per month is:

Enter the lower and upper limits for the conference interval by entering the lower limit first.
Rounded each conference limit to 1 decimal point.

____________

F     Prior to this study the owner of the Britten's Egg Farm Egg Farm believed the mean amount off eggs produced per month on his farm was 22.

Does the study support his belief with a 90% confidence?

a     Yes. The mean amount of eggs produced per month on his farm could be 22 per month because the number 22 is not contained in the confidence interval.

b     Yes. The mean amount of eggs produced per month on his farm could be 22 per month because the number 22 is contained in the confidence interval.

c     No. The mean amount of eggs produced per month on his farm is most likely not 22 per month because the number 22 is not contained in the confidence interval.

d     No. The mean amount of eggs produced per month on his farm is most likely not 22 per month because the number 22 is contained in the confidence interval.

e    The owner can not comment on the mean amount of eggs produced per month on his farm because the confidence interval is based upon a sample.

Enter the correct answer by selecting and entering the appropriate letter.

_____

Label the type of each variable listed in the dataset as either quantitative or categorical, and denote its scale of measurement (ratio, interval, ordinal, nominal).

• Wage (average hourly earnings)
• Education (years of education)
• Experience (years of experience)
• Tenure (length of time employed)
• Race
• Gender
• Married
• Dependents

home / study / math / statistics and probability / statistics and probability questions and answers / a survey found that​ women's heights are normally distributed with mean 62.3 in. and standard ... Your question has been answered Let us know if you got a helpful answer. Rate this answer Question: A survey found that​ women's heights are normally distributed with mean 62.3 in. and standard dev... A survey found that​ women's heights are normally distributed with mean 62.3 in. and standard deviation 2.9 in. The survey also found that​ men's heights are normally distributed with a mean 67.7 in. and standard deviation 2.9. a. Most of the live characters at an amusement park have height requirements with a minimum of 4 ft 8 in. and a maximum of 6 ft 3 in. Find the percentage of women meeting the height requirement. The percentage of women who meet the height requirement is . Find the percentage of men meeting the height requirement. The percentage of men who meet the height requirement is c. If the height requirements are changed to exclude only the tallest 5% of men and the shortest 5% of women, what are the new height requirements? The new height requirements are at least nothing in. and at most nothing in.

A random sample of 30 quart cartons of ice cream was taken from a large production run. Their mean fat content was 12.6 percent with a standard deviation of 1.25 percent. Based on this, do we believe that the average fat content in this type of ice cream is more than 12 percent? Use the 0.01 level of significance.

The lifetimes of a certain type of light bulbs follow a normal distribution. If 4% of the bulbs have lives exceeding 462 hours, and 40% have lives exceeding 372 hours, what are the mean and standard deviation of the lifetimes of this particular type of light bulbs? Round your answer to the nearest integer.

Mean = hours

Standard deviation = hours

3.

3. The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1x, for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant.

Step 1 of 6: Find the estimated slope. Round your answer to three decimal places.

Step 2 of 6: Find the estimated y-intercept. Round your answer to three decimal places.

Step 3 of 6: Determine if the statement "Not all points predicted by the linear model fall on the same line" is true or false.

Step 4 of 6: Substitute the values you found in steps 1 and 2 into the equation for the regression line to find the estimated linear model. According to this model, if the value of the independent variable is increased by one unit, then find the change in the dependent variable yˆ.

Step 5 of 6: Find the estimated value of y when x=44. Round your answer to three decimal places.

Step 6 of 6: Find the value of the coefficient of determination. Round your answer to three decimal places.

A random sample of size 9 from a distribution of ?(?, 36) yielded ?̅ = 40. Find the confidence intervals for ?

a. 99%

b. 97.5%

c. 95%

d. 90%

*Work the problems in EXCEL.

1. Problem 1:

=======>>>>>>Open data files: JeepSales.xlsx and JeepTable.xlsx ( copy this)

(a) Learn the PivotTable to derive JeepTables.xlsx from JeepSales.xlsx. [Hint: Click Insert,  

PivotTable, highlight the data]

(b) Construct a Frequency Bar chart, Pie chart.  

Reduce graph size. Copy/paste into a MS Word file.

2. Problem 2:   

=========>>>>>>Open data file: Design.xlsx. Construct,

(a) A Histogram with a revised Bin size. (Bin width =2).  

(b) A Frequency Polygon.  

(c) A Cumulative Percentage Histogram (ogive).

Reduce size. Copy and paste into the MS Word file.

1a)state the properties of characteristics roots
1b)state the features of principal component analysis
1c)what are the aims of principal component analysis
1d)given the vector X1 and X2 from a multivariate normal population, define the conditional distribution of X1

Suppose approximately 80% of all marketing personnel are extroverts, whereas about 60% of all computer programmers are introverts. (Round your answers to three decimal places.)
(a) At a meeting of 15 marketing personnel, what is the probability that 10 or more are extroverts?


What is the probability that 5 or more are extroverts?


What is the probability that all are extroverts?


(b) In a group of 5 computer programmers, what is the probability that none are introverts?


What is the probability that 3 or more are introverts?


What is the probability that all are introverts?

1.A- The government of River City, population 750,000, wants to know how best to allocate funds to serve its residents. Right now it is trying to determine whether to continue funding the "Concerts in the Park" summer music series. To gather data, it hires a firm that specializes in marketing research via telephone. The firm makes 200 calls asking respondents how often they attend the shows.

The size of the sample in question here is relatively (large/small) and the data (are/are not) likely to have significant outliers or large gaps in the values.

What is the best measure of centrality to use in this case? A-Mean ; B-median; C-Weighted mean ;D-Mode

1.B-Otis needs to know how many people his elevators can carry safely. He already knows how much weight they can bear before malfunctioning, so he needs to divide that by the average weight of a person. He uses a large pool of data from the federal government to calculate that average, which he then uses to estimate the largest group of people his elevators will safely accommodate.

The size of the sample in question here is relatively (large/small), and the data(are/are not) likely to have significant outliers or large gaps in the values.

What is the best measure of centrality to use in this case? A-Mean ; B-median; C-Weighted mean ;D-Mode

1.C-The Bakunin Banking Corp. employs 32 people. Upper management includes the CEO, who makes about $1.2 million per year with bonuses; the CFO, who earns $850,000; and three department heads, who each make between $700,000 and $750,000. The company also has two IT staff members, who each make $80,000. The rest of the employees work as clerks and earn between $20,000 and $27,000 dollars. The clerks are thinking about unionizing, and in making their case, they want to emphasize the disparate incomes at the firm.

The size of the sample in question here is relatively (large/small), and the data(are/are not) likely to have significant outliers or large gaps in the values.

What is the best measure of centrality to use in this case? A-Mean ; B-median; C-Weighted mean ;D-Mode

7) Skinner’s Fish Market buys fresh Boston bluefish daily for $4.20 per pound and sells it for $5.70 per pound. At the end of each business day, any remaining bluefish is sold to a producer of cat food for $2.40 per pound. Daily demand can be approximated by a normal distribution with a mean of 47 pounds and a standard deviation of 16 pounds. What is the optimal stocking level? Round your answer to 2 decimal places.

Times for a surgical procedure are normally distributed. There are two methods. Method A has a mean of 25 minutes and a standard deviation of 6 minutes, while method B has a mean of 29 minutes and a standard deviation of 3.0 minutes.

(a) Which procedure is preferred if the procedure must be completed within 25 minutes?

• Method A

• Method B

• Either Method

(b) Which procedure is preferred if the procedure must be completed within 35.0 minutes?

• Method A

• Method B

• Either Method

(c) Which procedure is preferred if the procedure must be completed within 33 minutes?

• Method A

• Method B

• Either Method

Five persons A, B, C, D, and E are seated at random in a row of seats numbered 1, 2, 3, 4, and 5.

a) Find the probability that A is seated on seat 2.

b) FInd the probability that A and B are not seated with each other.