Test Statistics

A manufacturer claimed that the average life of batteries used in their electronic games is 150 hours. It is known that the standard deviation of this type of battery is 20 hours. A consumer wished to test the manufacturer’s claim and accordingly tested 100 electronic games using the battery. It was found out that the mean is equal to 144 hours. What is the sample size?

• 100
• 144

• 20

• 150

A manufacturer claimed that the average life of batteries used in their electronic games is 150 hours. It is known that the standard deviation of this type of battery is 20 hours. A consumer wished to test the manufacturer’s claim and accordingly tested 100 electronic games using the battery. It was found out that the mean is equal to 144 hours. Is the population variance/standard deviation known or unknown?

• Partially known
• Maybe

• Known
• Unknown

A manufacturer claimed that the average life of batteries used in their electronic games is 150 hours. It is known that the standard deviation of this type of battery is 20 hours. A consumer wished to test the manufacturer’s claim and accordingly tested 100 electronic games using the battery. It was found out that the mean is equal to 144 hours. What is the appropriate test statistic?

• z test

• t test

• y test

• x test

An English teacher wanted to test whether the mean reading speed of students is 550 words per minute. A sample of 12 students revealed a sample mean of 540 words per minute with a standard deviation of 5 words per minute. At 0.05 significance level, is the reading speed different from 550 words per minute? What is the sample size?

• 12
• 550

• 540

• 0.05

An English teacher wanted to test whether the mean reading speed of students is 550 words per minute. A sample of 12 students revealed a sample mean of 540 words per minute with a standard deviation of 5 words per minute. At 0.05 significance level, is the reading speed different from 550 words per minute? What is the appropriate test statistic?

• z test

• t test

• y test

• x test

An English teacher wanted to test whether the mean reading speed of students is 550 words per minute. A sample of 12 students revealed a sample mean of 540 words per minute with a standard deviation of 5 words per minute. At 0.05 significance level, is the reading speed different from 550 words per minute? Is the population variance/standard deviation known or unknown?

• Partially known
• Maybe

• Known
• Unknown

A sample of n=25 is selected from a normal population,  x̄ = 56 and s = 12.

• z test

• t test

Based on the report of the school nurse, the average height of Grade 11 students has increased. Five years ago, the average height of Grade 11 students was 170cm with standard deviation of 38cm. She took a random sample of 150 students and derived the average height of 165cm.

• z test

• t test

Knowing from a previous study that the average of athletes is 80, an athletic adviser asked his soccer players a how re academically doing as compared other student athletes. After an initiative to help improve the average of student athletes, the adviser randomly selected soccer players 15 and found 85 as the average with standard deviation of 1.25.

• z test

• t test

The CEO of battery manufacturing company claimed a that their batteries would last an average of hours 280 under normal use. A researcher randomly selected 20 batteries from the production line and tested them. The tested batteries had a mean life span of 250 hours with a standard deviation of 40 hours. Do we have enough evidence to suggest that the claim of an average of 280 hours is false?

• z test

• t test