A random sample of n = 64 observations has a mean x = 29. 1, and a standard deviation of s = 3.9. Find a 90 % confidence interval for the population mean.. A major department store chain is interested in estimating the average amount its credit card customers spent on their first visit to the chain's new store in the mall. Fifteen credit card accounts were randomly sampled and analyzed with the following results: = $50.50 and = 400. Find a 95% confidence interval for the average amount the credit card customers spent on their first visit to the chain's new store in the mall.

Is there enough evidence in the data that population average price of diamond for color “E” is more than 1500?

Solve in R using the t test.

Assume the age of death for all us burials(of persons over 5 years old) is approximately normally distributed and the sample mean is 68.84 and the standard deviation is 18.402926789.

Find the age at death such that 1.5% of US burials (of persons over 5 years old) were at least that old.

Find the probability that a burial randomly selected from all US burials (of persons over 5 years old) involved a person at least 30 years old.

Find the probability that a burial randomly selected from all US burials ( of persons over 5 years old) involved a person at most 85 years old.

Which of the following are true about all normal distributions? Check all that apply
A. They are symmetric.
B. They are all centered at zero.
C. They have one large tail.
D. They are categorically sharp.

I chose A and D but I still get errors . I dont know if my answer wrong or I have to add one more

Probability Plot Problem:

Considering the following observations for X:

X = [19.0, 16.0, 14.0, 13.0, 12.0, 11.0, 10.5, 10, 9.7, 9.2, 8.7, 8.5]

a) Use Minitab to determine the type of probability distribution for X. Cut & paste the chart and briefly describe the reason for your answer.

b) Use the trendline in Excel to determine the equation f(x) for the observations. Cut & paste the chart with the trendline equation.

c) According to the above f(x), what is the predicted value of the next observation in the series?

_____________________________________________

Assume that 15​% of people are​ left-handed. If 6people are selected at​ random, find the probability of each outcome described below.

​a) Find the probability that the first lefty is the sixth person chosen.

​(Round to four decimal places as​ needed.)

​b) Find the probability that there are some lefties among the 6 people.

​(Round to four decimal places as​ needed.)

​c) Find the probability that the first lefty is the fourth or fifth person.

​(Round to four decimal places as​ needed.)

​d) Find the probability that there are exactly 2 lefties in the group.

​(Round to four decimal places as​ needed.)

​e) Find the probability that there are at least 4 lefties in the group.

​(Round to four decimal places as​ needed.)

​f) Find the probability that there are no more than 2 lefties in the group.

​(Round to four decimal places as​ needed.)

The time required
to assemble an electronic component
is normally distributed, with a mean of
12 minutes and a standard deviation of
1.5 minutes. Find the probability that a
particular assembly takes:
a less than 14 minutes
b less than 10 minutes
c more than 14 minutes
d more than 8 minutes
e between 10 and 15 minutes.

You submit your recommendations to your manager, and she tells you, “Thank you very much, but we have additional data for the Green Town Hopper: A 30% DOH results in a saving of 255 gallons per year. Please resubmit your recommendations taking this into account by tomorrow.” [hinT: You now have four data points on each graph, so try a general cubic instead: R 5 ax3 1 bx2 1 cx 1 d. Use a graph to estimate the optimal DOH

88 Discuss the appropriateness of the frequentist practice of keeping the level of a test constant irrespective of the sample size.

89 What is the pre-testing problem? What are your views about this problem?

90 What is the post-selection problem? What are your views about this problem?

I want to know how to solve the following in excel. What is the x value and what is the Y value using the data table below?

Wal-Mart is the second largest retailer in the world. The data file (Wal-Mart Revenue 2004-2009.xlsx) is posted below the case study one file, and it holds monthly data on Wal-Mart’s revenue, along with several possibly related economic variables.

A. Develop a linear regression model to predict Wal-Mart revenue, using CPI as the only independent variable.

B. Develop a linear regression model to predict Wal-Mart revenue, using Personal Consumption as the only independent variable.

C. Develop a linear regression model to predict Wal-Mart revenue, using Retail Sales Index as the only independent variable.

D. Which of these three models is the best? Use R-square values, Significance F values, p-values and other appropriate criteria to explain your answer.

E. Generate a scatter plot, residual plot and normal probability plot for the best model in part (d) and comment on what you see.

describe the negative impact of using inappropriate measurements, including examples

3. The average sale per customer at a department store is $120.00 with a standard deviation of $10.00.  

According to the Empirical Rule, the percentage of sales between

$90.00 and $150.00 would be   __________________

Using Chebyshev’s Theorem, the upper and lower limits for 75% of the data values =

_________to ___________.

c)    If a customer spends $160.00, which of the following is correct?

a) It is an outlier because it’s more than 3 standard deviations below the mean.

b) It is an outlier because it’s more than 3 standard deviations above the mean.

c) It is not an outlier.

d) None of the above is correct.

1. Sketch the area under the standard normal curve over the indicated interval and find the specified area. (Round your answer to four decimal places.)

The area to the right of z = 1.50 is _________

2. Sketch the area under the standard normal curve over the indicated interval and find the specified area. (Round your answer to four decimal places.)

The area to the left of  z = −1.33  is ________

3. Sketch the area under the standard normal curve over the indicated interval and find the specified area. (Round your answer to four decimal places.)

The area between  z = −2.25 and z = 1.41 is ________

4.Sketch the area under the standard normal curve over the indicated interval and find the specified area. (Round your answer to four decimal places.)

The area between z = −2.48 and z = −1.80 is ________

5. Assume that x has a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)

μ = 5.0; σ = 2.4.

P(3 ≤ x ≤ 6) = ________

6. Assume that x has a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)

μ = 109; σ = 12

P(x ≥ 90) = ________

An educational psychologist is examining response times to an on-screen stimulus. The researcher believes there might be a weak effect from age, but expects a more pronounced effect for different color contrasts. She decides to examine a black on white (B/W) combination compared to 2 alternatives: red on white (R/W) and yellow on blue (Y/B). Here is the data for response times (in milliseconds):

Using MS Excel, conduct a 2-way ANOVA with α=0.05α=0.05. Fill in the summary table:  P-values should be accurate to 4 decimal places and all other values accurate to 3 decimal places.

The table lists the sugar content of two types of apples from three different orchards. At , test the claim that the sugar content of the apples and the orchard where they were grown are not related. Sugar Content Orchard 1 Orchard 2 Orchard 3 Apple Type 1 4 2 6 Apple Type 2 28 10 14