Questions
Below is a distribution of race in the United States from 2014. White= 60.5% Black= 12.5%...

Below is a distribution of race in the United States from 2014.

White= 60.5%

Black= 12.5%

Hispanic= 18.3%

Asian= 5.7%

Other= 3%

If we were to randomly choose 150 people for a survey, what is the probability that less than 70 of them would be white (round to 3 decimal places)?

Would this be unusual? If so, give some reasons why a particular sample might have less than 70 whites.

What is the probability that we would randomly choose a sample of 150 people and more than 22 of them were black (to 3 decimal places)?

What is the probability you would randomly select two Americans and they would both be white?

How many Asian people should we expect to have in a randomly selected group of 150 people?

In: Math

Delta airlines quotes a flight time of 2 hours, 5 minutes for its flight from Cincinnati...

Delta airlines quotes a flight time of 2 hours, 5 minutes for its flight from Cincinnati to Tampa. Assume that the probability of a flight time within any one-minute interval is the same as the flight time within any other one-minute interval contained within the larger interval, 120 and 140 minutes.

*State the objective: What is the probability that the flight will be no more than 5 minutes late?

•Q1: What pdf best describes (models) the situation or assigns probabilities to outcomes of r.v.?

•Q2: Name and given values for parameters in the pdf.

•Q3: Define r. v.?

•Q4: Is r.v. discrete or continuous? (Make sure consistent with Q1)

•Q5: Write down the objective, question, or problem statement and then translate the English version into a statistics problem (using statistical and math language/formulas)

•Q6: Solve the objective.

In: Math

A random sample of 23 items is drawn from a population whose standard deviation is unknown....

A random sample of 23 items is drawn from a population whose standard deviation is unknown. The sample mean is x⎯⎯x¯ = 820 and the sample standard deviation is s = 25. Use Excel to find your answers.

(a)

Construct an interval estimate of μ with 99% confidence. (Round your answers to 3 decimal places.)

  The 99% confidence interval is from  to
(b)

Construct an interval estimate of μ with 99% confidence, assuming that s = 50. (Round your answers to 3 decimal places.)

  The 99% confidence interval is from  to
(c)

Construct an interval estimate of μ with 99% confidence, assuming that s = 100. (Round your answers to 3 decimal places.)

  The 99% confidence interval is from  to
(d)

Describe how the confidence interval changes as s increases.

The interval stays the same as s increases.
The interval gets wider as s increases.
The interval gets narrower as s increases.

In: Math

Read the following statements and decide if they are true sometimes, always or never. Be sure...

Read the following statements and decide if they are true sometimes, always or never. Be sure to give a reason for each statement or use an example and the reason why it shows the statement is false. You can download this document in the module one section Fractions and attach it if you prefer.

  1. All fractions are less than one
  2. Improper fractions are greater than or equal to one
  3. Proper fractions are less than one
  4. Fractions are always part of a whole
  5. All Fractions can be written as terminating decimals.
  6. When you create an equivalent fraction, you are multiplying by one.
  7. Numerators and denominators are always the same.

In: Math

These questions come from MBA 5008 1. What is the difference between a point estimate and...

These questions come from MBA 5008

1. What is the difference between a point estimate and a confidence interval?

2. Is a point estimate alone is adequate?

3. Evaluating the effect of variability measurement (confidence interval) on the resulting estimates.

In: Math

Assume that a simple random sample has been selected from a normally distributed population and test...

Assume that a simple random sample has been selected from a normally distributed population and test the given claim. Identify the null and alternative​ hypotheses, test​ statistic, P-value, and state the final conclusion that addresses the original claim.

A coin mint has a specification that a particular coin has a mean weight of 2.5 g. A sample of 36 coins was collected. Those coins have a mean weight of 2.49502g and a standard deviation of 0.01562

Use a 0.05 significance level to test the claim that this sample is from a population with a mean weight equal to 2.5g

Do the coins appear to conform to the specifications of the coin​ mint?

test statistic z=

p=

In: Math

A researcher studied the relationship between the salary of a working woman with school-aged children and...

A researcher studied the relationship between the salary of a working woman with school-aged children and the number of children she had. The results are shown in the following frequency table:

                                             Number of Children

Salary

2 or fewer children

more than 2 children

high salary

13

2

medium salary

20

10

low salary

30

25

         If a working woman has more than 2 children, what is the probability she has a low or medium salary?

         A.      0.79            B.      0.45            C.      0.35            D.      0.95

In: Math

Q 1.An online retailer, Mr Collins Ndhlovu, has two adverts posted in different parts of a...

Q 1.An online retailer, Mr Collins Ndhlovu, has two adverts posted in different parts of a well-known social networking website, Advertisement A and Advertisement B. An average of 2 ‘clicks’ are generated by Advertisement A during the period Monday 10.00 to 10.05am. There are on average 5 ‘clicks’ generated by Advertisement B during the same period. Calculate the probability that on a particular Monday between 10.00 and 10.05 am: i)Advertisement A generates at most 3 clicks. ii)Advertisement A generates at least 4 clicks. ii)Advertisement B generates no more than 4 clicks. iv)Advertisement A generates exactly 2 clicks and Advertisement B exactly 2 clicks. v)At least 3 clicks are generated in total by the two advertisements. (5marks)

In: Math

Explain the difference between a confidence interval and a prediction interval?

Explain the difference between a confidence interval and a prediction interval?

In: Math

The National Association of Home Builders provided data on the cost of the two most popular...

The National Association of Home Builders provided data on the cost of the two most popular home remodeling projects. Sample data on cost in thousands of dollars for two types of remodeling projects are as follows.

Kitchen Master Bedroom Kitchen Master Bedroom
27.0 18.0 23.0 17.8
17.4 21.1 19.7 24.6
22.8 26.4 16.9 22.0
21.9 24.8 21.8
21.0 25.4 19.0

Using Kitchen as population 1 and Master Bedroom as population 2, develop a point estimate of the difference between the population mean remodeling costs for the two types of projects (to 1 decimal).
$   thousand

Develop a 90% confidence interval for the difference between the two population means (to 1 decimal). Use z-table.
( ,  )

In: Math

A recent survey reported that 39​% of​ 18- to​ 29-year-olds in a certain country own tablets....

A recent survey reported that 39​% of​ 18- to​ 29-year-olds in a certain country own tablets. Using the binomial​ distribution, complete parts​ (a) through​ (e) below.

a. What is the probability that in the next six​ 18- to​ 29-year-olds surveyed, four will own a​ tablet?

The probability is ? (Type an integer or a decimal. Round to four decimal places as​ needed.)

b. What is the probability that in the next six​ 18- to​ 29-year-olds surveyed, all six will own a​ tablet?

c. What is the probability that in the next six​ 18- to​ 29-year-olds surveyed, at least four will own a​ tablet?

d. What are the mean and standard deviation of the number of​ 18- to​ 29-year-olds who will own a tablet in a survey of​ six?

e. What​ assumption(s) do you need to make in​ (a) through​ (c)?

In: Math

The computer that controls a bank's automatic teller machine crashes a mean of 0.4 0.4 times...

The computer that controls a bank's automatic teller machine crashes a mean of 0.4 0.4 times per day. What is the probability that, in any seven-day week, the computer will crash less than 4 4 times? Round your answer to four decimal places.

In: Math

Describe the kind of data that are collected for an independent-measures t-test and the hypotheses that...

Describe the kind of data that are collected for an independent-measures t-test and the hypotheses that the test evaluates. The key to helping formulate your explanation would be to include the assumptions of this statistical model, the type of sample used in this model, and a statement about the null hypothesis.

In: Math

Calculate a geometric series 1.For v greater than 0 and less than 1, what is the...

Calculate a geometric series

1.For v greater than 0 and less than 1, what is the Sum(v^i) for i = 1 to 100?

2.For v greater than 0 and less than 1, what is the Sum(v^i) for i = 1 to infinity?

3.Let v = 1/(1+r). State the answer to question 2 in terms of r.

In: Math

Question 1 contains the actual values for 12 periods (listed in order, 1-12). In Excel, create...

Question 1 contains the actual values for 12 periods (listed in order, 1-12). In Excel, create forecasts for periods 6-13 using each of the following methods: 5 period simple moving average; 4 period weighted moving average (0.63, 0.26, 0.08, 0.03); exponential smoothing (alpha = 0.23 and the forecast for period 5 = 53); linear regression with the equation based on all 12 periods; and quadratic regression with the equation based on all 12 periods.  Round all numerical answers to two decimal places.

1. The actual values for 12 periods (shown in order) are:

(1) 45  (2) 52 (3) 48 (4) 59  (5) 55  (6) 54  (7) 64  (8) 59  (9) 72  (10) 66  (11) 67  (12) 78

Using a 5 period simple moving average, the forecast for period 13 will be:

2.  
Using the 4 period weighted moving average, the forecast for period 13 will be:

3.
With exponential smoothing, the forecast for period 13 will be

4.
With linear regression, the forecast for period 13 will be:

5.
With quadratic regression, the forecast for period 13 will be:

6.
Considering only the forecasts for period 6-12, what is the lowest MAD value for any of the methods?

In: Math