A random sample of n1 = 49 measurements from a
population with population standard deviation σ1 = 5 had
a sample mean of x1 = 8. An independent random sample of
n2 = 64 measurements from a second population with
population standard deviation σ2 = 6 had a sample mean
of x2 = 11. Test the claim that the population means are
different. Use level of significance 0.01.
(a) Check Requirements: What distribution does the sample test
statistic follow? Explain....
A population has a mean of 180 and a standard deviation of 36. A
sample of 84 observations will be taken. The probability that the
sample mean will be between 181 and 185 is
A population has a mean of 180 and a standard deviation of 24. A
sample of 64 observations will be taken. The probability that the
sample mean will be between 183 and 186 is
A population has a mean of 37.6 and a standard deviation of
14.8. A sample of 75 will be taken. Find the probability that the
sample mean will be greater than 42.0.
a) Calculate the z score. (Round your answer to 2 decimals.)
b) Find the probability that the sample mean will be greater than
42.0. (Round your answer to 4 decimals.)
A population has a mean of 245.3 and a standard deviation of
12.6. A sample of 200 will be taken. Find the probability that the
sample mean will be less than 248.4.
a) Calculate the z score. (Round your answer to 2 decimals.)
b) Find the probability that the sample mean will be less than
248.4. (Round your answer to 4 decimals.)
A population has a mean of 300 and a standard deviation of 18.
A sample of 144 observations will be taken. The probability that
the sample mean will be less than 303 is
0.4332
0.9772
0.9544
0.0668
None of the above
A population has a mean of 180 and a standard deviation of 24. A
sample of 64 observations will be taken. The probability that the
sample mean will be within 3 of the population mean is:
A population has a mean of 180 and a standard deviation of 24. A
sample of 64 observations will be taken. The probability that the
sample mean will be less than or equal to 186 is
A population has a mean of 80 and a standard deviation of 7. A
sample of 49 observations will be taken. The probability that the
mean from that sample will be larger than 81 is
0.1587
0.0062
0.0228
0.0668
A population has a mean of 161.2 and a standard deviation of
9.6. A sample of size 13 is taken from this population. What is the
standard deviation of the sampling distribution of the
mean? Enter your answer to 3 decimal places.
We have two random variables, A and B. A has a mean of 74.6 and
a standard deviation of 36.4. B has a mean of 35.7 and a standard
deviation of 19.4. If we create a new random variable...