Assume the cholesterol levels in a certain population have mean μ = 200 and standard deviation σ = 24. The cholesterol levels for a random sample of n = 9 individuals are measured and the sample mean x-bar is determined. What is the z-score for a sample mean x = 180?

Related MCQs

• You conduct a hypothesis test and you observe values for the sample mean and sample standard deviation when n = 25 that do not lead to the rejection of Ho (null hypothesis). You calculate a p-value of 0.0667. What will happen to the p-value if you observe the same sample mean and standard deviation for a sample n>25?
• Consider that for a process s bar (average standard deviation of 50 samples each of size 4) is found to be 10.04. The value of c4 (corresponding to sample size of .4) is .92. What is the estimated value of process standard deviation?
• Random variance in a process, as measured by the standard deviation, can be directly reduced by:
• Consider the first method of p bar estimation where each sample is of varying size. If the 3rd sample has p bar =.01, and the sample size of the 3rd sample is 10, what will be the upper control limit for the 3rd sample?
• The standard normal distribution has mean= ______________ and standard deviation= ______________.
• You are sampling items from a batch and plotting the results on a control chart. How will an increase in the number of items sample affect the value of the standard deviation used to set the control limit?
• Suppose box A contains 4 red and 5 blue coins and box B contains 6 red and 3 blue coins. A coin is chosen at random from the box A and placed in box B. Finally, a coin is chosen at random from among those now in box B. What is the probability a blue coin was transferred from box A to box B given that the coin chosen from box B is red?
• Factory A produces 100 pieces of wooden legs used in manufacturing tables in 1 hour. The factory in total works for 3 hours. The quality manager decided to check the quality of the output by measuring the length of the legs (in cms). He decides to collect three samples (one for each hour). The sample size for each sample is fixed at 5. The data collected is present in the following table: What is the mean and range of leg length in sample 1?
• While random variability in a system can be removed by ______________, non-random variability requires ______________.
• A larger standard deviation for a normal distribution with an unchanged mean indicates that ‘the distribution becomes: