Question

In: Statistics and Probability

The diameter of holes for cable harness is known to have a standard deviation of 0.01...

The diameter of holes for cable harness is known to have a standard deviation of 0.01 in. A random sample of size 10 yields an average diameter of 1.5045 in. Use α=0.01 to:

a. Test the hypothesis that the true mean whole diameter equal 1.5 in.

b. What sample size would be necessary to detect a true mean hole diameter of 1.505 in. with probability of at least 0.95?

c. What is the type II error if the true mean hole diameter is 1.504 in.?

Solutions

Expert Solution

It should be noted that as the sample size increases, the sample mean tends toward the population mean. Hence, the confidence interval size is large when n is small for a given probability ( i.e. we are more unsure of the mean).

The extreme points of this interval represent the critical values for the sampled mean.


Related Solutions

The diameter of alloy rods produced on an extrusion machine are known to have a standard...
The diameter of alloy rods produced on an extrusion machine are known to have a standard deviation of 0.0001 inches. A random sample of 25 rods have a mean diameter of 0.5046 inches. a) Test the hypothesis that the mean diameter is 0.5025 inches. Assume a 2-sided alternative and use α=.05. Be sure to identify the decision rule, the critical values. Draw pictures to visualize. b) Construct the 2-sided 95% confidence interval for this test with α=.05. c) What is...
1. From a population of 540 that is known to have a standard deviation of 1,368,...
1. From a population of 540 that is known to have a standard deviation of 1,368, a sample of 60 individuals. The mean of this sample is found to be 6.2. a) Find the standard error of the mean. b) Construct an interval estimate around the sample mean, using the standard error of the mean calculated for 96% of cases. 2. A test of car safety in the State of Carolina found that the tire pressure for a sample of...
A certain IQ test is known to have a population mean of 100 and standard deviation...
A certain IQ test is known to have a population mean of 100 and standard deviation of 15 in the general population. You want to test whether psychology majors have a different average IQ than the population as a whole. Assume the variance of IQ is the same for Psych majors as it is in the general population. Suppose that Psychology majors actually have an average IQ of 108. If you do a 2-tailed test at α= .05 with a...
The population of all verbal GRE scores are known to have a standard deviation of 8.5....
The population of all verbal GRE scores are known to have a standard deviation of 8.5. The UW Psychology department hopes to receive applicants with a verbal GRE scores over 210. This year, the mean verbal GRE scores for the 42 applicants was 212.79. Using a value of α = 0.05 is this new mean significantly greater than the desired mean of 210? a. Is this a one tailed or two tailed test? Why? b. Conduct the appropriate hypothesis test...
a. If you know the variance of a portfolio es 0.01. What is the standard deviation?...
a. If you know the variance of a portfolio es 0.01. What is the standard deviation? If the expected return of the portfolio is 5%, what is a possible interval where the return can be? b. If the weights on your portfolio composed of three assets are 20%, 30% and 50% and the expected return on the same assets are 4%, 6%, and 7.5%, respectively. What is the expected return on the portfolio? c. If you invest 20% in asset...
A special cable has breaking strength of 800 pounds. the standard deviation of the population is...
A special cable has breaking strength of 800 pounds. the standard deviation of the population is 12 pounds . A research selects a sample of 20 cables and finds that the average breaking strength is 793 pounds. test the claim that breaking strength is less than 800 pounds. Should the null hypothesis be rejected at a=0.01? Assuming that the variable is normally distributed.
(1) American ladybugs have an average adult length of 1 cm with a known standard deviation...
(1) American ladybugs have an average adult length of 1 cm with a known standard deviation of 0.2 cm. The population of American ladybugs in Raleigh was around 1914000 last spring. Assume a normal distribution for the lengths of adult American ladybugs. Your niece asks you what's the probability of a random ladybug in Raleigh being bigger than 1.5 cm. Is it appropriate to calculate this probability? Select one: a. Yes. b. No, because the population distribution is skewed. c....
Suppose you have a distribution with known mean (m) and standard deviation (s). What happens to...
Suppose you have a distribution with known mean (m) and standard deviation (s). What happens to these two measures if you multiply all observations by 5? (i) The new mean will be 5m, and the standard deviation 5s (ii) Both the mean and the standard deviation will stay the same (iii) The new mean will be m+5, and the standard deviation equal to s
Using 7/8 in diameter ASTM A325-N bolts in standard holes and E70 electrodes. Design a bolted...
Using 7/8 in diameter ASTM A325-N bolts in standard holes and E70 electrodes. Design a bolted flange-plated FR moment connection between a W12×50 beam and a W14×90 column flange (RD = 15 kips; MD = 60 kip-ft) and (RL = 30 kips; ML = 120 kip-ft). For shear plate use three bolts:(i)Check the beam available flexural strength (ii)Design single-plate web connection (iii)Check the connecting elements rupture strength at welds Sketch the connection.
Using 7/8 in diameter ASTM A325-N bolts in standard holes and E70 electrodes. Design a bolted...
Using 7/8 in diameter ASTM A325-N bolts in standard holes and E70 electrodes. Design a bolted flange-plated FR moment connection between a W12×50 beam and a W14×90 column flange (RD = 15 kips; MD = 60 kip-ft) and (RL = 30 kips; ML = 120 kip-ft). For shear plate use three bolts: (I) Check the beam available flexural strength (ii) Design single-plate web connection (iii) Check the connecting elements rupture strength at welds Sketch the connection.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT