Statistics and Probability Answers

The average height of students in a freshman class of a certain school has been 158.55 cm with a population standard deviation of 8.8 cm. Is there a reason to believe that there has been a change in the average height if a random sample of 51 students in the present freshman class has an average height of 154.25 cm? Use a 0.1 level of significance.

What are the given? Write only the number. :

population mean:Blank 1 cm

population standard deviation:Blank 2 cm

sample size:Blank 3

sample mean:Blank 4 cm

level of significance:Blank 5

What are the critical values? Write the positive critical value first then the negative.

z:Blank 6 andBlank 7

What is the value of the calculated z? Round your answer to the nearest hundredths.

z:Blank 8

"It is claimed that a car is driven on the average less than 28700 kilometers per year with a population standard deviation of 2100 kilometers. To test this claim, a random sample of 58 car owners are asked to keep a record of the kilometers they travelled. Would you agree with this claim if the random sample showed an average of 22500 kilometers? Use a 0.01 level of significance.

What are the given? Write only the number. :

population mean:Blank 1 km

population standard deviation:Blank 2 km

sample size:Blank 3

sample mean:Blank 4 km

level of significance:Blank 5

What is the critical value?

z:Blank 6

What is the value of the calculated z? Round your answer to the nearest hundredths.

z:Blank 7"

The average height of students in a freshman class of a certain school has been 158.55 cm with a population standard deviation of 8.8 cm. Is there a reason to believe that there has been a change in the average height if a random sample of 51 students in the present freshman class has an average height of 154.25 cm? Use a 0.1 level of significance.

What are the given? Write only the number. :

population mean:Blank 1 cm

population standard deviation:Blank 2 cm

sample size:Blank 3

sample mean:Blank 4 cm

level of significance:Blank 5

What are the critical values? Write the positive critical value first then the negative.

z:Blank 6 andBlank 7

What is the value of the calculated z? Round your answer to the nearest hundredths.

z:Blank 8

Given the population 1,3,4,6 and 8. Suppose samples of size 3 are drawn from this population.

How many different samples can be drawn from this population?

A fair spinner has 9 equal sections: 3 red, 2 blue and 4 green.

It is spun twice.

What is the probability of not getting two consecutive blues?

For a 95% confidence level, what are the critical values for a one-tailed test?

According to one survey in India, 75% of Instagram users love REELS. Suppose that 25

Instagram users (randomly selected) have been approached in the university located in vile

parle. They have been asked about their status of like/ dislike the Instagram- REELS.

a) What is the probability that Exactly 15 of them would agree with the claim (or said they

love Insta-REELS)?

b) What is the probability that Exactly 20 of them would agree with the claim (or said they

love Insta-REELS)?

What is the probability that the 36 tires will have an

average of less than 16,000 miles until the tires begin

to wear out

A new machine is being considered to replace the old machine being used. This new machine was tested for 10 consecutive hours with the following output: 119, 122, 118, 122, 120, 124, 126, 125, 125, and 124. If the average output per hour using the old machine is 120 units, is the management justified in stating that the output per hour can be increased with the new machine? Use a 0.01 level of significance

A study claims tha.t on average, male high school students spend at least 3.39 hours a day playing video games with a standard deviation of 2.05 hours. A random sample of 30 teenagers were surveyed and the results showed that these teenagers spend 4.12 hours a day playing video games.

Solve for the z-score of the sample mean of 4.12 hours