Many psychologists are concerned that the average level of anxiety in children has increased over the past 40 years. In the 1980s, the population average score on the ChildManifest Anxiety Scale (CMAS) was 15.1. In 2021, a random sample of 101 children was tested with CMAS. The mean for the sample was 16.1 with the standard deviation of4. Is there enough evidence to claim that there has been a significant change in the average level of anxiety since the 1980s? Conduct the appropriate statistical test (two-tailed) with a = .05.Based on the estimated Cohen's d, the magnitude of change in the average level of anxiety since the 1980s could best be qualified as:O Very largeO LargeO No changeOSmall

The formula of the Cohens’d is,Thresholds value of d is as follows:If d=0.20, the effect size is…

Answered: Many psychologists are concerned that…

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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Similar questions

Mr. Dela Cruz works for a New York theatrical agency whose employees had an average income last year of $28,000 with a standard deviation of $3,000. How much did Mr. dela Cruz earn last year if his z score is -0.8?O $25,600O -$30,400O $11,400O $45,600O $30,400
in a test of a lifelong brand of tires , a survey revealed that the mean life was 35,000 mikes and the standard deviation was 7083 mikes. if the shape of the population distribution is known to be normal, approximately what percentage of the tires lasts less than 20834 miles ?
An article in the San Jose Mercury News stated that students in the California state universitysystem take 4.25 years, on average, to finish their undergraduate degrees. Suppose you believe that the mean time is longer. You conduct a survey of 64 students and obtain a sample mean of 4.5 with a sample standard deviation of 1.5. Do the data support your claim at the 1% level?
Solar energy is considered by many to be the energy of the future. A recent survey was taken to compare the cost of solar energy to the cost of gas or electric energy. Results of the survey revealed that the distribution of the amount of the monthly utility bill of a three-bedroom house using gas or electric energy had a mean of $117 and a standard deviation of $13. If the distribution can be considered normal: Approximately what percentage of homes will have a monthly utility bill less than $78? Note: Do NOT include the "%" sign Do NOT round any decimals, if applicable
On the PSAT test taken by about 1.5 million high school juniors each year, the mean score on the reading portion of the test was 46.9, with a standard deviation of 10.9. The scores are normally distributed. If a student needed a score on this portion of the test that put them in the top 5% of scores nationally to qualify for a particular scholarship, what is the minimum score they must achieve?
In 1974, the mean height of a woman in the United States was 63.7 inches, with a standard deviation of 2.5 inches. What is the height of a woman who is taller than 88% of the rest of the sample? Enter your answer in inches rounded to one decimal place, e.g. 60.4.
Suppose there is a city where the mean cost per month of a one-bedroom apartment is $1,500, with a standard deviation of $250. Approximately what percentage of one-bedroom apartments in the city cost between $750 and $1,000?
A successful basketball player has a height of 6 feet 11 inches, or 211 cm. Based on statistics from a data set, his height converts to the z score of 5.17. How many standard deviations is his height above the mean?
In the class of 2019, more than 1.6 million students took the SAT. The distribution of scores on the math section (out of 800) is approximately normal with a mean of 528 and standard deviation of 117. What proportion of students earned scores between 500 and 600 on the SAT math test?
Suppose we know that the aspirin content of aspirin tablets follows a Normal distribution with standard deviation of o= 5 mg.
According to Chebyshev's Rule, at least what percent of observations must be within 2.5 standard deviations from the mean? [a]%
The mean amount of money spent per week on gas by a sample of 32 Oxford drivers was found to be $32.38 with a standard deviation of $2.63. Step 4 of 4: Suppose it is reported that the national mean amount of money spent per week on gas is $33.Is there evidence that the true mean for Oxford drivers differs from $33?

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