Question 2: A survey is conducted to estimate the average amount spent on utilities for households in a city. 20 clusters are selected by SRSWOR from 60 clusters of the city. Interviewers then obtain the cost of utilities from each household within the sampled clusters; the total costs are shown in the accompany table. \begin{tabular}{|l|c|c|l|c|c|} \hline \begin{tabular}{l} Sampled \\ Cluster \end{tabular} & \begin{tabular}{l} Number of \\ households \end{tabular} & \begin{tabular}{l} Total amount \\ Spent on utilities \end{tabular} & \begin{tabular}{l} Sampled \\ Cluster \end{tabular} & \begin{tabular}{l} Number of \\ households \end{tabular} & \begin{tabular}{l} Total amount \\ Spent on utilities \end{tabular} \\ \hline 1 & 55 & 2210 & 11 & 73 & 2930 \\ \hline 2 & 60 & 2390 & 12 & 64 & 2470 \\ \hline 3 & 63 & 2430 & 13 & 69 & 2830 \\ \hline 4 & 58 & 2380 & 14 & 58 & 2370 \\ \hline 5 & 71 & 2760 & 15 & 63 & 2390 \\ \hline 6 & 78 & 3110 & 16 & 75 & 2870 \\ \hline 7 & 69 & 2780 & 17 & 78 & 3210 \\ \hline 8 & 58 & 2370 & 18 & 51 & 2430 \\ \hline 9 & 52 & 1990 & 19 & 67 & 2730 \\ \hline 10 & 71 & 2810 & 20 & 70 & 2880 \\ \hline \end{tabular} (a) Estimate the average amount a household in the city spends on utilities. (b) Construct a \( 95 \% \) C.I. for the average amount with an unbiased estimate of the variance. (c) Find an unbiased estimate for the total amount spent on utilities of all households in the city. (d) Determine a bound \( B_{a} \) on the absolute error of estimating the total amount with a probability of 0.95 and an unbiased estimate of the variance. (e) Use (d) to construct a \( 95 \% \) C.I. for the total amount. Use \( z_{0.025}=1.96 \) to answer Question 2.
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For each cluster, divide the total amount spent on utilities by the number of households in that cluster. For example, for Cluster 1: \[ \text{Average per household} = \frac{2210}{55} \approx 40.18 \] Repeat this calculation for all 20 clusters. Show moreā¦
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An economic survey is designed to estimate the average amount spent on utilities for households in a city. Since no list of households is available, cluster sampling is used, with wards forming the clusters. A simple random sample of 20 wards is selected from the 60 wards of the city. Interviewers then obtain the cost of utilities from each household within the sampled wards; the total costs are shown in the accompanying table. Sampled ward | Number of households | Total amount ($) spent on utilities | Sampled ward | Number of households | Total amount ($) spent on utilities 1 | 55 | 2210 | 11 | 73 | 2930 2 | 60 | 2390 | 12 | 64 | 2470 3 | 63 | 2430 | 13 | 69 | 2830 4 | 58 | 2380 | 14 | 58 | 2370 5 | 71 | 2760 | 15 | 63 | 2390 6 | 78 | 3110 | 16 | 75 | 2870 7 | 69 | 2780 | 17 | 78 | 3210 8 | 58 | 2370 | 18 | 51 | 2430 9 | 52 | 1990 | 19 | 67 | 2730 10 | 71 | 2810 | 20 | 70 | 2880 a. Estimate the average amount a household in the city spends on utilities. b. Find the variance. c. Although the number of households in the city is unknown. Estimate the total amount spent on utilities for all households in the city. d. Find the variance.
Sri K.
Areen D.
Lucas F.
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