Question

The compressive strength of concrete is normally distributed with μ = 2500 psi and σ =...

The compressive strength of concrete is normally distributed with μ = 2500 psi and σ = 50 psi. A random sample of n = 5 specimens is taken. What is the standard error of the sample mean?

A)

2500

B)

10

C)

22.36

D)

50
Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

Given,

Since, the population is normally distributed, so according to the central limit theorem, the distribution of sample is normally distributed with mean and variance

Therefore, standard error of sample mean is

Answer is C).

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The compressive strength of concrete is normally distributed. A random sample of 11 concrete specimens from...
The compressive strength of concrete is normally distributed. A random sample of 11 concrete specimens from Factory 1 yields a sample mean equal to 1,221.3 pounds per square inch (psi) and a sample variance of 882.0 psi2. A random sample of 11 concrete specimens from Factory 2 yields a sample mean equal to 1,441.2 psi and a sample variance of 856.1 psi2.   If you do a test of hypothesis to see if the means of the concretes from Factory 1...
Suppose that the compressive strength of concrete is normally distributed with an unknown mu and a...
Suppose that the compressive strength of concrete is normally distributed with an unknown mu and a known sigma of 40 (pounds per square inch). A random sample of size 19 has sample mean 1376. Construct a 92% confidence interval (as crazy and unlikely as it seems to create a 92% CI) for the population mean. Give answer to one decimal place.
Testing of a given concrete sample has yielded a normal distribution with a mean compressive strength...
Testing of a given concrete sample has yielded a normal distribution with a mean compressive strength of 3200 psi with a standard deviation of 275 psi. You require a compressive strength of at least 2950 psi.  What is the probability that this concrete meets your needs?
We measured the compressive strength for n = 16 specimens of concrete. Using the mean and...
We measured the compressive strength for n = 16 specimens of concrete. Using the mean and standard deviation and assuming a normal population, we computed the following confidence interval [2271.7688, 2308.2312]. This interval is a confidence interval for the mean compressive strength at a level of confidence of 90%. We are told the the sample mean is x = 2290. What is the value of the sample standard deviation s?
A synthetic fiber used in manufacturing carpet has tensile strength that is normally distributed with mean...
A synthetic fiber used in manufacturing carpet has tensile strength that is normally distributed with mean 75.5 psi and standard deviation 3.5 psi. Find the probability that a random sample of n=7 fiber specimens will have a sample mean tensile strength that exceeds 75.8 psi. Round your answer to two decimal places.
If a population is distributed with a mean μ and a standard deviation σ, then the...
If a population is distributed with a mean μ and a standard deviation σ, then the distribution of sample means is distributed A) normally with mean μ and standard deviation σ. B) normally with mean μ and standard deviation σ/√(n). C) with mean μ and standard deviation σ. D) with mean μ and standard deviation σ/√(n).
An engineer studying the tensile strength of a composite material knows that tensile strength is approximately...
An engineer studying the tensile strength of a composite material knows that tensile strength is approximately normally distributed with σ = 60 psi. A random sample of 20 specimens has a mean tensile strength of 3450 psi. (a) Test the hypothesis that the mean tensile strength is 3500 psi, using α = 0.01 (b) What is the smallest level of significance at which you would be willing to reject the null hypothesis? (c) What is the β error for the...
An engineer who is studying the tensile strength of a steel alloy knows that tensile strength...
An engineer who is studying the tensile strength of a steel alloy knows that tensile strength is approximately normally distributed with σ = 60 psi. A random sample of 12 specimens has a mean tensile strength of 3450 psi. a) How would the confidence interval change if we did not know that σ = 60 psi, but the number of specimens is 80? b) How would the confidence interval change if we did not know that σ = 60 psi,...
The accompanying data is on cube compressive strength (MPa) of concrete specimens. 112.5      97.0     ...
The accompanying data is on cube compressive strength (MPa) of concrete specimens. 112.5      97.0      92.6      86.0      102.0 99.1      95.8      103.5      89.0      86.6 (a) Is it plausible that the compressive strength for this type of concrete is normally distributed? The normal probability plot is not acceptably linear, suggesting that a normal population distribution is plausible. The normal probability plot is acceptably linear, suggesting that a normal population distribution is plausible.     The normal probability...
A new concrete mix is being designed to provide adequate compressive strength for concrete blocks. The...
A new concrete mix is being designed to provide adequate compressive strength for concrete blocks. The specification for a particular application calls for the blocks to have a mean compressive strength µ greater than 1350 kPa. A sample of 100 blocks is produced and tested. Their mean compressive strength is 1356 kPa and their standard deviation is 70 kPa. What is the most appropriate null hypothesis regarding the population mean µ. Indicate the alternate hypothesis as well. Find the P-value....
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT