Start Spring 2024Question 5,HW Score: 73.89%,8.1.17-T4.43 of 6 pointsPart 4 of 4Points: 0.5 of 1SaveA simple random sample of size n=10 is obtained from a population with μ=63 and σ=15.(a) What must be true regarding the distribution of the population in order to use the normal model to compute probabilities involving the sample mean? Assuming that this condition is true, describe the sampling distribution of xˉ.(b) Assuming the normal model can be used, determine P(xˉ<66.4).(c) Assuming the normal model can be used, determine P(x≥64.2).(a) What must be true regarding the distribution of the population?A. The sampling distribution must be assumed to be normal.B. Since the sample size is large enough, the population distribution doe need to be normal.C. The population must be normally distributed and the sample size must be large.D. The population must be normally distributed.Assuming the normal model can be used, describe the sampling distribution xˉ. Choose the correct answer below.A. Normal, with μxˉ=63 and σxˉ=15B. Normal, with μxˉ=63 and n=101C. Normal, with μxˉ=63 and n=103(b) n=104 (Round to four decimal places as needed.)(c) n=105 (Round to four decimal places as needed.)
Q. Start Spring 2024Question 5,HW Score: 73.89%,8.1.17-T4.43 of 6 pointsPart 4 of 4Points: 0.5 of 1SaveA simple random sample of size n=10 is obtained from a population with μ=63 and σ=15.(a) What must be true regarding the distribution of the population in order to use the normal model to compute probabilities involving the sample mean? Assuming that this condition is true, describe the sampling distribution of xˉ.(b) Assuming the normal model can be used, determine P(xˉ<66.4).(c) Assuming the normal model can be used, determine P(x≥64.2).(a) What must be true regarding the distribution of the population?A. The sampling distribution must be assumed to be normal.B. Since the sample size is large enough, the population distribution doe need to be normal.C. The population must be normally distributed and the sample size must be large.D. The population must be normally distributed.Assuming the normal model can be used, describe the sampling distribution xˉ. Choose the correct answer below.A. Normal, with μxˉ=63 and σxˉ=15B. Normal, with μxˉ=63 and n=101C. Normal, with μxˉ=63 and n=103(b) n=104 (Round to four decimal places as needed.)(c) n=105 (Round to four decimal places as needed.)
Condition for Normal Model: Determine the condition needed for using the normal model for the sample mean. The population must be normally distributed since the sample size n=10 is not large enough to rely on the Central Limit Theorem alone.
Sampling Distribution of Sample Mean: Describe the sampling distribution of the sample mean xˉ assuming the normal model can be used. The correct answer is C: Normal, with μxˉ=63 and σxˉ=1015. This is because the standard deviation of the sample mean σxˉ is the population standard deviation σ divided by the square root of the sample size n.
Calculate P(xˉ<66.4): Calculate P(xˉ<66.4) using the normal distribution. First, find the z-score:Z=σ/nX−μZ=15/1066.4−63Z=0.7217Using the Z-table or a calculator, find P(Z<0.7217)=0.7642.
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