Are America's top chief executive officers (CEOs) really worth all that money? One way to answer this question is to look at row B, the annual company percentage increase in revenue, versus row A, the CEO's annual percentage salary increase in that same company. Suppose that a random sample of companies yielded the following data:

Do these data indicate that the population mean percentage increase in corporate revenue (row B) is different from the population mean percentage increase in CEO salary? Use a 5% level of significance. Find (or estimate) the P-value.

A manufacturer knows that their items have a lengths that are skewed right, with a mean of 15.8 inches, and standard deviation of 4.7 inches.

If 35 items are chosen at random, what is the probability that their mean length is greater than 13.9 inches?

The data set is a study of student persistent enrolling in the next semester based on Gender, Age, GPA, a 22 questionnaire on self-efficacy, and student enrollment status.The educational researcher wants to study the relationship between student enrollment status as it relates to gender, age, GPA, and the total response to a 22 questionnaire survey.

2. The estimated multiple regression analysis equation.

3. Does the model work?

4. How well does the model work?

5. Which variables contribute to the model?

6. General interpretation of the data and the data analysis

After years of meteorological investigation, daily rainfall over a region in the North of India is supposed to be distributed as a Normal distribution with mean 22.6mm and variance 41.7mm2.

2. A day is classified as abnormally wet if rainfall levels are greater than or equal to 35mm. What is the probability of having an abnormally wet day?

3. A period of 14 days is considered. What is the probability that one abnormally wet day will be observed during this period?

Sixty students were asked during finals week to choose their favorite treat to eat while studying. They were given four choices (cake, cookies, ice cream, donuts) and asked to choose one. Their data were as follows:

Cake 10

Cookies 12

Ice Cream 20

Donuts 18

Using an alpha of .05, conduct a hypothesis test by hand using all steps of hypothesis testing to examine the following research question: Is there a difference in students’ preferred choice of treat? Go through all of the steps in hypothesis testing including:

a) State your hypotheses.

b) Find the df and critical value(s)

c) Compute the test statistic by hand

d) Make a decision

e) Calculate effect size, if needed

f) Write your results sentence(s). Include your test statistic in journal form

1. A polling organization talks to several people concerning what is their preferred method of obtaining political news.

The table breaks the information by age.

a. [3] What proportion of respondents

preferred where age 31 to 55 or preferred to get political news via internet sources?

b. [3] Of the respondents that preferred to get political news via printed publication what percentage where 56 and over?

c. [3] Show that the events a person is 18 to 30, a person prefers to get political news via television are not independent events.

My question is that should I accept or reject the null hypothesis?

Variable 1: General Health / Ordinal

Variable 2: Body Mass Index / Continuous

Null hypothesis: There is no statistically significant relationship between general health and body mass index. (In other words, correlation coefficient is equal or close to zero.)

Research/Alternative hypothesis: There is a statistically significant relationship between general health and body mass index. (In other words, correlation coefficient is different/far from zero.)

Statistical analysis used: Spearman’s (rank-order) correlation analysis

Key statistics:

Correlation coefficient: r = 0.248 (weak positive)

Statistical significance: p = 0.000 (statistically significant at level 0.01)

Coefficient of determination/Shared variance/Effect size/Practical significance (r2) = 0.248  * 0.248  = 0.062 (small)

0.062 *100= 6.2%. This means that 6.2% of the change/variance/variability in variable #1 (General Health)explains change/variance/variability in variable #2 (Body Mass Index). In other words, these two variables share 6.2% variance. This also means that 93.8% of variance in each of these variables remain unexplained/unaccounted for.

Assumptions:

1.Outliers: Scatterplot and boxplot show some significant outliers in the data.

2.Normality: Normality was assessed using Shapiro-Wilk’s test, and the distribution of the two variables are statistically significantly different from normal distribution (p = 0.000, p < .05).

3.Linearity: Scatterplot doesn’t demonstrate any linear relationship between these two variables (General Health and Body Mass Index). The scatterplot shows vertical lines with each category.

Accept or reject the null: Accept the null hypothesis and reject the research hypothesis. Although the p value show that data is statistically significant, the correlation coefficient is weak and effect size is small. Moreover, the data didn’t meet any of the assumptions.

My question is that should I accept or reject the null hypothesis?

. Four hundred melanoma patients were diagnosed according to the type of skin cancer and the location of the skin cancer. This data is presented below. What proportion of patients had superficial spreading melanoma? Of patients with a skin cancer on the trunk, what proportion had a nodular skin cancer? What proportion of patients had a Hutchinson’s melanomic freckle on the extremities? Is type of skin cancer independent of location? Justify your answer. Location Type Head and Neck Trunk Extremities Total Hutchinson’s melanomic freckle 22 2 10 34 Indeterminate 11 17 28 56 Nodular 19 33 73 125 Superficial spreading melanoma 16 54 115 185 Total 68 106 226 400

USE EXCEL TO SOLVE

Joan’s Nursery specializes in custom-designed landscaping for residential areas. The estimated labor cost associated with a particular landscaping proposal is based on the number of plantings of trees, shrubs, and so on to be used for the project. For cost-estimating purposes, managers use two hours of labor time for the planting of a medium sized tree. Actual times from a sample of 10 plantings during the past month follow (times in hours):

1.7 1.5 2.4 2.2 1.9 2.3 2.1 1.6 1.4 2.3

At the 10% significance level test using p-value method to see whether the mean tree-planting time is less than two hours?

List different properties one can use when describing the shape of the distribution.

The data for a random sample of 10 paired observations are shown in the following table.

1. If you wish to test whether these data are sufficient to indicate that the mean for population 2 is larger than that for population 1, what are the appropriate null and alternative hypotheses? Define any symbols you use.

2. Conduct the test from part a, using α=.05. What is your decision?

3. Find a 95% confidence interval for μd. Interpret this interval.

4. What assumptions are necessary to ensure the validity of the preceding analysis?

In 2005, 0.76% of all airline flights were on-time. If we choose a simple random sample of 2000 flights, find the probability that... (to four decimal places, using normal chart, no continuity correction)

(a) at least 79% of the sample's flights were on time

(b) at most 1580 of the sample's flights were on time

(c) the sample proportion of on-time flights (p-hat) differs from the truth by more than three percent

Please double-check, provide work, and show explanation

Assume I toss a fair coin exactly 17 times. Find the probability of the following outcomes:

A) 4 tails

B) 17 tails

C) 5 heads

D) 17 heads

E) 13 or more tails

F) 5 or fewer tails

Eric wants to estimate the percentage of elementary school children who have a social media account. He surveys 450 elementary school children and finds that 280 have a social media account. Identify the values needed to calculate a confidence interval at the 99% confidence level. Then find the confidence interval. z0.10 z0.05 z0.025 z0.01 z0.005 1.282 1.645 1.960 2.326 2.576

The director of the IRS has been flooded with complaints that people must wait more than 35 minutes before seeing an IRS representative. To determine the validity of these complaints, the IRS randomly selects 400 people entering IRS offices across the country and records the times which they must wait before seeing an IRS representative. The average waiting time for the sample is 50 minutes with a standard deviation of 23 minutes. Is there overwhelming evidence to support the claim that the wait time to see an IRS representative is more than 35 minutes at a 0.025 significance level?

Step 1 of 3 :

Find the value of the test statistic. Round your answer to three decimal places, if necessary.