Which of the following is not a characteristic of the chi-square distribution? Select all correct answers.
Select all that apply:
The chi-square curve is symmetrical.
The chi-square curve is skewed to the left.
The total area under the χ2-curve is equal to the degrees of freedom, df.
The total area under the χ2-curve is equal to 1.
Does buying CDs depend on whether you own a smartphone or not? A survey asks a group of students if they buy CDs or not. It also asks if the students own a smartphone or not. The data are recorded in the contingency table below, and a chi-square Test of Independence at the 5% significance level is performed.
CDs |
No CDs |
Row Total |
|
Smartphone |
6 |
24 |
30 |
No Smartphone |
16 |
8 |
24 |
Column Total |
22 |
32 |
54 |
(a) The null and alternative hypotheses are:
(b) Compute the test statistic, rounded to one decimal place. (Use expected frequencies that are also rounded to one decimal place.)
Provide your answer below: test statistics =
Horace keeps track of the amount of time he studies and the score he gets on his quiz. The data are shown in the table below. Which of the scatter plots below accurately records the data?
Hours studying |
Quiz score |
1 |
4 |
2 |
6 |
3 |
7 |
4 |
8 |
5 |
9 |
Select the correct answer below:
A scatterplot has a horizontal axis labeled Hours studying from 0 to 10 in increments of 2 and a vertical axis labeled Quiz score from 0 to 6 in increments of 1. Five plotted points strictly follow the pattern of a line that rises from left to right and has the following coordinates: left-parenthesis 4 comma 1 right-parentheses; left-parenthesis 6 comma 2 right-parentheses; left-parenthesis 7 comma 3 right-parentheses; left-parenthesis 8 comma 4 right-parentheses; left-parenthesis 9 comma 5 right-parentheses. Each point is labeled with its vertical coordinate.
A scatterplot has a horizontal axis labeled from 0 to 6 in increments of 1 titled Hours studying and a vertical axis labeled from 0 to 10 in increments of 2 titled Quiz score. The following points are plotted: left-parenthesis 1 comma 4 right-parenthesis; left-parenthesis 2 comma 6 right-parenthesis; left-parenthesis 3 comma 7 right-parenthesis; left-parenthesis 4 comma 9 right-parenthesis; left-parenthesis 5 comma 8 right-parenthesis.
A scatterplot has a horizontal axis labeled from 0 to 6 in increments of 1 titled Hours studying and a vertical axis labeled from 0 to 10 in increments of 2 titled Quiz score. The following points are plotted: left-parenthesis 1 comma 4 right-parenthesis; left-parenthesis 2 comma 6 right-parenthesis; left-parenthesis 3 comma 7 right-parenthesis; left-parenthesis 4 comma 8 right-parenthesis; left-parenthesis 5 comma 9 right-parenthesis.
Which of the following is not a characteristic of the chi-square distribution? Select all correct answers....
Commute Time (in minutes) Well-Being Score 6 69.9 14 68.4 26 67.6 34 67.1 47 66.5 73 65.2 105 63.5 (a) Which variable is likely the explanatory variable and which is the response variable? A. The explanatory variable is commute time and the response variable is the well-being score because well-being score affects the commute time score. B. The explanatory variable is the well-being score and the response variable is commute time because commute time affects the well-being score. C....
Following are age and price data for 8 randomly selected ambulances between 1 and 6 years old. Here, x denotes age, in years, and y denotes price, in hundreds of dollars. Use the information to complete parts (a) through (f). x 6 1 6 2 6 2 4 5 y 280 410 255 350 250 370 335 300 a. Find the regression equation for the data points. ModifyingAbove y with caretyequals=nothingplus+nothingx (Round to two decimal places as needed.) b....
A company that produces cell phones claims its standard phone battery lasts longer on average than other batteries in the market. To support this claim, the company publishes an ad reporting the results of a recent experiment showing that under normal usage, their batteries last at least 35 hours. To investigate this claim, a consumer advocacy group asked the company for the raw data, which are shown to the right. Find a 95% confidence interval and state your conclusion. Explain...
A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 753 hours. A random sample of 20 light bulbs has a mean life of 732 hours. Assume the population is normally distributed and the population standard deviation is 61 hours. At α=0.02, do you have enough evidence to reject the manufacturer's claim? Complete parts (a) through (e). (a) Identify the null hypothesis and alternative hypothesis. A. H0: μ<732 (claim) Ha: μ≥732...
Effect size for the chi-square test for independence 1.Which of the following statements are correct about the phi-coefficient? Check all that apply. a.It can be used as a measure of the significance of a relationship between two dichotomous variables. b.It is the same as Cramer’s V when the data are a 2 x 2 matrix. c.It can be used as a measure of the strength of a relationship between two dichotomous variables. d.It can be used as a measure of...
Given the plot of normal distributions A and B below, which of the following statements is true? Select all correct answers. A normal bell curve labeled Upper A and a normal elongated curve labeled Upper B are centered at the same point. Normal curve Upper B is narrower and above normal curve Upper A. Select all that apply: A has the larger mean. B has the larger mean. The means of A and B are equal. A has the larger...