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 an average speed of 62 words per minute was obtained with a standard deviation of 8. Can we say that the sample students performance is below the standard deviation at the 0.05 level of significance.
Did you find an error or inaccuracy? Feel free to write us. Thank you!
Thank you for submitting an example text correction or rephasing. We will review the example in a short time and work on the publish it.
Tips to related online calculators
You need to know the following knowledge to solve this word math problem:
We encourage you to watch this tutorial video on this math problem: video1
Related math problems and questions:
- Confidence Interval
The average grade of 50 students senior students in a statistics class is 85 with a standard deviation of 10.2 while a group of 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
- 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 were given the same test and showed an average score of 83.20. Is there evidence to show that this group ha
- Math test
Students wrote a math test. The average number of points obtained by them was 64. Another student wrote this test for 80 points. If the teacher added his result to the original ones, the total average of all students would be 65. How many students origina
- Chi square
A manufacturer of phone batteries claims that his batteries' lives are approximately normally distributed with a standard deviation equal to 0.9 years. If a random sample of 10 of these batteries has a standard deviation of 1.2 years. Do you think that th
Calculate standard deviation for file: 63,65,68,69,69,72,75,76,77,79,79,80,82,83,84,88,90
- Typing course
Before taking a typing course, Terrence could type 39 words per minute. By the end of the course, he was able to type 68 words per minute. Find the percent increase.
- Standard deviation
Find standard deviation for dataset (grouped data): Age (years) No. Of Persons 0-10 15 10-20 15 20-30 23 30-40 22 40-50 25 50-60 10 60-70 5 70-80 10
- Average speed
The car drove on one section of the highway for half an hour at a speed of 80 km/h. Then he reduced his speed to 60km/h. It went three-quarters of an hour at a speed of 60 km/h. What was the average speed of the car?
Stoaches are fictional creatures distantly related to bigfoot and yeti. Stoach weights are normally distributed, with mean 904g and standard deviation 104g. State the probability that the sample mean of a random sample of 36 stoach weights exceeds 943g. (
What is the average speed of the car, where half of the distance covered passed at speed 66 km/h and the other half at 86 km/h.
In one region, the September energy consumption levels for single-family homes are found to be normally distributed with a mean of 1050 kWh and a standard deviation of of 218 kWh. Find the consumption level separating the bottom 45% from the top 55%.
- 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 n
- Average height
In a class are 34 students. The average height of the students is 165 cm. What will be the average height of students in the classroom when two pupils, tall 176 cm and 170 cm, moved from this school/class?
- Unemployment rate
Over the last 16 years, the country's unemployment rate has changed according to the following frequency table: years of unemployment: 2 5 2 3 3 1 unemploymen rate: 0.5 1 1.5 2 2.5 3 in % (percent). Determine the two-sided confidence interval for the vari
- Speed of Slovakian trains
Rudolf decided to take the train from the station 'Ostratice' to 'Horné Ozorovce'. In the train timetables found train Os 5409 : km 0 Chynorany 15:17 5 Ostratice 15:23 15:23 8 Rybany 15:27 15:27 10 Dolné Naštice 15:31 15:31 14 Bánovce nad Bebravou 15:35 1
- 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?
Output Controller of the company in the control of 50 randomly selected products found that 37 of them had no defects, 8 has only one flaw, three had two defects, and two products had three defects. Determine the standard deviation and coefficient of vari