Practice Math Statistics Problems and Master the Concepts

For continuous random variables X and Y with joint probability density function
$f (x, y) = {\begin{cases} x e^{- (x + x y)} & x > 0 a n d y > 0 \\ 0 & o t h e r w i s e \end{cases}$
Are X and Y independent? Explain.

Zoe Oneal 2021-10-18

It appears that there is some truth to the old adage “That which doesn’t kill us makes us stronger.” Seery, Holman, and Silver (2010) found that individuals with some history of adversity report better mental health and higher well-being compared to people with little or no history of adversity. In an attempt to examine this phenomenon, a researcher surveys a group of college students to determine the negative life events that they experienced in the past 5 years and their current feeling of well-being. For $n = 16$ participants with 2 or fewer negative experiences, the average well-being score is $M = 42$ with $S S = 398$ , and for $n = 16$ participants with 5 to 10 negative experiences the average score is $M = 48.6$ with $S S = 370$ .
1. Is there a significant difference between the two populations represented by these two samples? Use a two-tailed test with $α = .01$ [use the 4-step procedure]. [Remember to assess whether the assumption of homogeneity of variances is satisfied or not, $α = .01$ for homogeneity test].
2. Compute Cohen’s d to measure the size of the effect.
3. Report your hypothesis test results and cohen’s d in APA format.

Jaden Easton 2021-10-18

A study was performed comparing different nonpharmacologic treatments for people with high-normal diastolic blood pressure (DBP) (80-89 mm Hg). One of the modes of treatment studied was stress management. People were randomly assigned to a stress management intervention (SMI) group or a control group. Participants randomized to SMI were given instructions in a group setting conserning different techniques for stress management and met periodically over a 1-month period. Participants randomized to the control group were advised to pursue their normal lifestyles and were told that their blood pressure would be closely monitored and that their physician would be notified of any consistent elevation. The results for the SMI group $(n = 242)$ at the end of the study (18 months) were as follows:
Mean (change) $= - 5.53 m m$ Hg (follow-up - baseline), sd (change) $= 6.48 m m$ Hg.
How much power did the study have for detecting a significant difference between groups (using a two-sided test with a $5 %$ level of significance) if the true effect of the SMI intervention is to reduce mean DBP by 2mm Hg more than the control group and the standard deviation of change within a group is 6mm Hg?

BenoguigoliB 2021-10-18

Iranian researchers studied factors affecting patients’ likelihood of wearing orthodontic appliances, noting that orthodontics is perhaps the area of health care with the highest need for patient cooperation (Behenam & Pooya, 2007). Among their analyses, they compared students in primary school, junior high school, and high school. The data that follow have almost exactly the same means as the researchers found in their study, but with far smaller samples. The score for each student is his or her daily hours of wearing the orthodontic appliance. Did age of students impact how long they wore the orthodontic appliance for? Use alpha of .05.
Primary school: $16, 13, 18 (M = 15.67, s = 2.52)$
Junior high school: $8, 13, 14, 12 (M = 11.75, s = 2.63)$
High school: $20, 15, 16, 18 (M = 17.25, s = 2.22)$

cistG 2021-10-17

Test whether the claim that the two sample groups come from populations with the same mean or not.

vazelinahS 2021-10-17

What is the example of Pearson correlation coefficient and what is the functions?

necessaryh 2021-10-17

Describe the basic characteristics that define an independent-measures, or a between-subjects, research study.

glasskerfu 2021-10-17

Random variables $X_{1}, X_{2}, \dots, X_{n}$ are independent and identically distributed; 0 is a parameter of their distribution.
State the definition for a pivotal function of X, the vector of random variables, and 0.

a2linetagadaW 2021-10-17

Let X be a random variable with probability density function.
$f (x) = {\begin{cases} c (1 - x^{2}) - 1 < x < 1 \\ 0 otherwise \end{cases}$
(a) What is the value of c? (b) What is the cumulative distribution function of X?

Khadija Wells 2021-10-17

Reporting summary measures such as the mean, median, and standard deviation has become very common in modern life. Many companies, government agencies will report these descriptive measures of a variable, but they will rarely provide information on the shape of the distribution of that variable. In previous tutorials, you have learned some basic properties of some distributions that can help you to decide if a specific type of distribution is a good fit for a set of data.
According to the National Diet and Nutrition Survey: Adults Aged 19 to 64, British men spend an average of 2.15 hours per day in moderate or high intensity physical activity. The standard deviation of these activity times for this sample was 3.59 hours. Can we infer that these activity times could follow a normal distribution? The following may provide an answer.
Suppose that the standard deviation for this sample was 0.70 hours instead of 3.59 hours, which make it numerically possible for the distribution to be normal. Again, considering the variable being measured, explain why the normal distribution is still not a logical choice for this distribution.

Bergen 2021-10-16

what is the use of spss in data analysis and why is it considered important

glamrockqueen7 2021-10-16

The ? relative frequencies are the sums of each row and column in a two-way table. (joint, marginal, or conditional)

emancipezN 2021-10-16

Suppose we are testing $H_{o} : p = 0.20$ vs $H_{a} : p$ does not equal 0.20 and $T S = 2.34$ . What is the p-value?

Chaya Galloway 2021-10-16

The probability distribution of the random variable X represents the number of hits a baseball player obtained in a game for the 2012 baseball season.
$\begin{array}{cc} x & P (x) \\ 0 & 0.167 \\ 1 & 0.3289 \\ 2 & 0.2801 \\ 3 & 0.149 \\ 4 & 0.0382 \\ 5 & 0.0368 \end{array}$
The probability distribution was used along with statistical software to simulate 25 repetitions of the experiment (25 games). The number of hits was recorded. Approximate the mean and standard deviation of the random variable X based on the simulation. The simulation was repeated by performing 50 repetitions of the experiment. Approximate the mean and standard deviation of the random variable. Compare your results to the theoretical mean and standard deviation. What property is being illustrated?
a) Compute the theoretical mean of the random variable X for the given probability distribution.
$μ = ?$
b) Compute the theoretical standard deviation of the random variable X for the given probability distribution.
$σ = ?$
c) Approximate the mean of the random variable X based on the simulation for 25 games.
$\overset{―}{X} = ?$
d) Approximate the standard deviation of the random variable X based on the simulation for 25 games.
$S = ?$

iohanetc 2021-10-16

MODELING REAL LIFE. You mix 0.25 cup of juice concentrate for every 2 cus of water to make 18 cups of juice. How much juice concentrate do you use? How much water do you use?
$Y o u u s e B \otimes \cup s o f j u i c e c o n c e n t r a t e and B \otimes \cup s o f w a t e r$ .

Dolly Robinson 2021-10-16

Learning math The Core Plus Mathematics Project (CPMP) is an innovative approach to teaching Math- ematics that engages students in group investigations and mathematical modeling. After field tests in 36 high schools over a three-year period, researchers compared the performances of CPMP students with those taught using a traditional curriculum. In one test, students had to solve applied Algebra problems using calculators. Scores for 320 CPMP students were compared to those of a control group of 273 students in a traditional Math pro- gram. Computer software was used to create a confidence interval for the difference in mean scores. (Journal for Research in Mathematics Education, 31, no. 3[2000]) Conf level: 95% Variable: Mu(CPMP) – Mu(Ctrl) Interval: (5.573, 11.427) a) What’s the margin of error for this confidence interval? b) If we had created a 98% CI, would the margin of error be larger or smaller?c) Explain what the calculated interval means in context. d) Does this result suggest that students who learn Mathematics with CPMP will have significantly higher mean scores in Algebra than those in traditional programs? Explain.

Phoebe 2021-10-16

1) Whether the method of sampling is dependent or independent.
2) To explain: Whether the response variable is qualitative or quantitative.

Emeli Hagan 2021-10-16

a) Explain whether the situation involves comparing proportions for two groups or comparing two proportions from the same group.
Also, check whether the methods of the section apply to the difference in proportions.
b) Explain whether the situation involves comparing proportions for two groups or comparing two proportions from the same group. Also, check whether the methods of the section apply to the difference in proportions.
c) Explain whether the situation involves comparing proportions for two groups or comparing two proportions from the same group. Also, check whether the methods of the section apply to the difference in proportions.
d) Explain whether the situation involves comparing proportions for two groups or comparing two proportions from the same group. Also, check whether the methods of the section apply to the difference in proportions.

ka1leE 2021-10-15

To explain: The use of the one-way analysis of variance.

Kaycee Roche 2021-10-15

1). What is the difference between a t-test for independent samples and a t-test for dependent samples? 2). Provide one study that would be analyzed using a t-Test for dependent samples; then provide one study that would be analyzed using a t-Test for independent samples

It’s not surprising that we encounter numerous ""I need help with statistics problems"" requests online because these are met everywhere, not only in economics or engineering. The majority of college statistics problems are also met in Sociology, Journalism, Healthcare, and Political Science. As long as you have statistics problems with solutions and answers, you will find solutions. Take a look at our college statistics math problems to find the answers. These will help college statistics problems be resolved. As you seek help with statistics problems, take your time to explore provided solutions and compare them with your initial instructions.

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