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A confidence interval for μ1 − μ2 can be constructed, write down the expression.

Four male monkeys were raised individually, and their testosterone levels were measured. They were then put together in the same cage and, after two months, their testosterone was measured again. The mean of the difference scores for testosterone level (time 2 minus time 1) was Mp= 2.70. The standard deviation of the difference scores (Sp) = 2.54. Test the hypothesis that when male monkeys live with others (time 2) they have higher testosterone levels %3D

A 95% confidence interval for the mean was computed with a sample of size 90 to be (16,22). Then the Error is ±3.

A 95% confidence interval for the mean was computed with a sample of size 100 to be (10,14). Then the Error is ±2.  true or false

Find tα/2 when n=12  for the  95% confidence interval for the mean.

The records of 100 postal employees who volunteered for a study, showed that the average time these employees had worked for the postal service was x̅=8 years. Assume that we know that the standard deviation of the population of time postal service employees have spent with the postal service is approximately normal with a standard deviation of σ=5 years. A 95% confidence interval for the meantime μ the population of postal service employees have spent with the postal service is?

The melting points of two alloys used in formulating solder were investigated by melting 21 samples of each material. The sample mean and standard deviation for alloy 1 was īi = 420°F and si = T2 = 426°F and s2 = 3°F. Find a 95% confidence interval on the difference in 4°F , and for alloy 2, they were %3D the two means. (-0.061, 0.861) -4.119, 15.129) (-8.205, –3.795) (1.857, 18.943)

Describe about CONFIDENCE INTERVALS FOR μ BASED ON t.

A random sample of 50 ladybirds of a particular species is collected, and the length of each ladybird measured to the nearest millimetre, giving a sample mean of 6.5 millimetres, and a sample standard deviation of 2 millimetres. Find an 99% confidence interval for the population mean length of ladybirds of this species, giving each limit in millimetres to 2 decimal places.

Now suppose we take a random sample of 20 CU Boulder students and find that the sample mean for amount of time spend each week engaged in coursework is x = 31.4 hours. Let's further assume the population standard deviation is still o = 2.8 hours. 5. Construct a 90% confidence interval for the true mean time that CU Boulder students spend each week engaged in coursework. In addition to the interval estimate, your solution should include the values for za/2' the standard error O and the margin of error ( Za, 6. Based on your confidence interval above, is it reasonable to say CU Boulder students spend more time engaged in coursework each week compared to CU Denver students? EXPLAIN. 7. Use the t-table and/or Excel to complete the table below. Confidence Level df Za/2 ta/2 2 90 0.10 35 95 28 98 61 99 19

A population of score has μ = 90. In this population, a score of X = 100 correponds to z = 5. what is the population standard deviation?

Four male monkeys were raised individually, and their testosterone levels were measured. They were then put together in the same cage and, after two months, their testosterone was measured again. The mean of the difference scores for testosterone level (time 2 minus time 1) was Mp= 2.70. The standard deviation of the difference scores (Sp)= 2.54. Test the hypothesis that when male monkeys live with others (time 2) they have higher testosterone levels than when they live alone (time 1). Use alpha = 0.05.