Question

In a certain country, the average age is 31 years old and the standard deviation is...

In a certain country, the average age is 31 years old and the standard deviation is 4 years. If we select a simple random sample of 100 people from this country, what is the probability that the average age of our sample is at least 32?

0.006

0.599

0.401

0.994

Homework Answers

Answer #1

Solution :

Given that ,

mean = = 31

standard deviation = = 4

n = 100

= 31

= / n = 4 / 100 = 0.4

P( ) = 1 - P( < 32)

= 1 - P[( - ) / < (32 - 31) / 0.4]

= 1 - P(z < 2.5)

= 0.006

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Suppose that the Average student is 20.6 years with a standard deviation of 1.7 years. Suppose...
Suppose that the Average student is 20.6 years with a standard deviation of 1.7 years. Suppose we obtain a simple random sample of 100 students ages. 1) What is the expected sample average age? 2) What is the standard deviation of the sample average? 3) Find the probability that the sample average is at least 21.3 years.
The average retirement age for a certain country was reported to be 56.3 years according to...
The average retirement age for a certain country was reported to be 56.3 years according to an international group dedicated to promoting trade and economic growth. With the pension system operating with a​ deficit, a bill was introduced by the government during the summer to raise the minimum retirement age from 60 to 62. Suppose a survey of 50 retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire. Assume...
the average age of doctors in a certain hospital is 50.0 years old. Suppose the distribution...
the average age of doctors in a certain hospital is 50.0 years old. Suppose the distribution of ages is normal and has a standard deviation of 6.0 years. If nine doctors are chosen at random for a committee, find the probability that the average age of those doctors is less than 50.6. Assume that the variable is normally distributed
The average retirement age for a certain country was reported to be 57.8 years according to...
The average retirement age for a certain country was reported to be 57.8 years according to an international group dedicated to promoting trade and economic growth. With the pension system operating with a? deficit, a bill was introduced by the government during the summer to raise the minimum retirement age from 60 to 62. Suppose a survey of 35 retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire. Assume...
Suppose the average lifespan of a lab rat is 3.4 years with a standard deviation of...
Suppose the average lifespan of a lab rat is 3.4 years with a standard deviation of 0.8 years. If we obtain a simple random sample of 64 lab rats, what is the probability that the sample average lifespan is at least 3.65 years? a) 0.0062 b) 0.9938 c) 0.4052 d) 0.0485 e) 0.9515
The average age of child advocates is 34.5 years, with a standard deviation of 24 years....
The average age of child advocates is 34.5 years, with a standard deviation of 24 years. If a county employs 64 child advocates, find the probability that the average age of the group is no less than 29.7 years old.
Assume the average age of an MBA student is 31.7 years old with a standard deviation...
Assume the average age of an MBA student is 31.7 years old with a standard deviation of 2.6 years. ​a) Determine the coefficient of variation. ​b) Calculate the​ z-score for an MBA student who is 26 years old. ​c) Using the empirical​ rule, determine the range of ages that will include 95​% of the students around the mean. ​d) Using​ Chebyshev's Theorem, determine the range of ages that will include at least 92​% of the students around the mean. ​e)...
Assume the average age of an MBA student is 29.1 years old with a standard deviation...
Assume the average age of an MBA student is 29.1 years old with a standard deviation of 2.6 years. ​a) Determine the coefficient of variation. ​b) Calculate the​ z-score for an MBA student who is 24 years old. ​c) Using the empirical​ rule, determine the range of ages that will include 99.7​% of the students around the mean. ​d) Using​ Chebyshev's Theorem, determine the range of ages that will include at least 96​% of the students around the mean. ​e)...
The mean age when smokers first start is 13 years old with a population standard deviation...
The mean age when smokers first start is 13 years old with a population standard deviation of 1.8 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS—electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 35 smokers found that their mean starting age was 12.1 years old. Do the data support the claim at the 10% significance level? What...
he mean age of graduate students at a University is thought to be 31 years old....
he mean age of graduate students at a University is thought to be 31 years old. A random sample of 15 graduate students is taken. The sample mean age is 33 years and the sample standard deviation is three years. Does the sample data indicate that the population mean age is actually greater than 31 years old? Use a 1% level of significance. a.) What is α? State the null and alternate hypotheses. Will you use a left-tailed, right-tailed, or...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT