Performance comparing
A standardized test was administered to thousands of students with a mean score of 85 and a standard deviation of 8. A random sample of 50 students was given the same test and showed an average score of 83.20. Is there evidence to show that this group has a lower performance than the ones in general at a 0.05 level?
Result
Result
Showing 1 comment:
Miro
For p value we use our normal distribution calcuator:
https://www.hackmath.net/en/calculator/normal-distribution?mean=0&sd=1&above=-1&area=below&below=-1.591&ll=&ul=&outsideLL=&outsideUL=&draw=Calculate
https://www.hackmath.net/en/calculator/normal-distribution?mean=0&sd=1&above=-1&area=below&below=-1.591&ll=&ul=&outsideLL=&outsideUL=&draw=Calculate
Tips for related online calculators
Looking for help with calculating arithmetic mean?
Looking for a statistical calculator?
Looking for a standard deviation calculator?
Looking for a statistical calculator?
Looking for a standard deviation calculator?
You need to know the following knowledge to solve this word math problem:
Grade of the word problem:
We encourage you to watch this tutorial video on this math problem: video1
Related math problems and questions:
- A professor
A professor in a typing class found out that the average performance of an expert typist is 85 words per minute. A random sample of 16 students took the typing test, and we obtained an average speed of 62 words per minute with a standard deviation of 8. C - IQ Intelligence quotient
Intelligence quotient (IQ) is a standardized score used as the output of standardized intelligence psychological tests to quantify a person's intelligence with the rest of the population (respectively, to a given group). Intelligence has an approximately - Confidence Interval
The average grade of 50 senior students in a statistics class is 85, with a standard deviation of 10.2. In comparison, 60 senior students got an average of 80 with a standard deviation of 8.9. Can the difference in the mean grade be attributed to chance, - 3 sigma
Students' performance scores in a statistic test have a mean of 70 and a standard deviation of 4.0. The scores obtained can be modeled by a normal distribution. Find the probability that the score of a randomly selected student is i. more than 80 marks ii - A biologist A biologist knows that the average length of a leaf of a certain plant is 4 inches. The standard deviation of the population is 0.6 inches. A sample of 20 leaves of that type of plant given a new type of plant food had an average length of 4.2 inches. At
- A student 2 A student randomly selected 225 college students and asked whether they had eaten breakfast that morning before coming to campus. Fifty-seven students were at least 25 years old, and 30 had breakfast that morning. Of the 168 students younger than 25, 82 h
- Two methods A teacher wishes two methods of teaching verbs to his English class. He divided the class randomly into two samples of 14 students each. Using Method 1, the students learned an average of 43.8 with a standard deviation of 4.6, while the second group (Meth
- Suppose 8 Suppose the scores on a test have a normal distribution with X=74 and a standard deviation of s=18. What percentage of students have scores higher than 90? What percentage of students have scores between 70 and 85? Twenty percent of the students do better
- Two sigma
Khail took his math test and scored 88. If the class average was 78 with a standard deviation of 5, what percent of students earned a higher grade than Khail's grade? - Chi square
A phone battery manufacturer claims that his battery lives are approximately normally distributed with a standard deviation equal to 0.9 years. Suppose a random sample of 10 of these batteries has a standard deviation of 1.2 years. Do you think that the s - 20 students
Twenty students took a test. Ten students got an average (arithmetic mean) score of 80. Five of them got an average score of 75. And the remaining 5 students got an average score of 55. What is the average score of the 20 students? - Manufacturing company
A random sample of 8 manufacturing companies is selected from a population of manufacturing companies. The market values (in millions of rands) of these eight manufacturing companies are: 17 65 117 206 172 181 221 94 What is the lowest and highest market - Std-deviation
Calculate standard deviation for file: 63,65,68,69,69,72,75,76,77,79,79,80,82,83,84,88,90 - Average height
There are twice as many girls in the class as there are boys. The average height of girls is 177 cm, boys 186 cm. What is the average height of students in this class? - Level of significance At a certain college, it is estimated that 25% of the students have cars on campus. Does this seem to be a valid estimate if, in a random sample of 90 college students, 28 are found to have cars? Use a 0.05 level of significance.
- Final exam
There are five learners in a class that has written a final exam. Aleta scored 55%, Vera scored 36%, and Sibusiso scored 88%. If Thoko scored 71% and the class average was 63%. What was Davids's score as a percentage? - Z-score 3 A random variable X has a mean of 4 and a standard deviation of 2. What is the corresponding z-score for x = 7?
