(b) What is the point estimate of the difference between the two population means? (Use mean score first round - mean score fourth round.) For which round is the population mean score lower? O The mean of the fourth round scores was lower than the mean of the first round scores. O The mean of the first round scores was lower than the mean of the fourth round scores. (c) What is the margin of error for a 90% confidence interval estimate for the difference between the population means? (Round your answer to two decimal places.) Could this confidence interval have been used to test the hypothesis in part (a)? Explain. O Yes. One could check to see if the 90% confidence interval includes a difference of zero. If the interval does not contain zero, the difference is not statistically significant. O Yes. One could check to see if the 90% confidence interval includes a difference of one. If the interval does not contain one, the difference is not statistically significant. O Yes. One could check to see if the 90% confidence interval includes a difference of zero. If the interval contains zero, the difference is not statistically significant. O Yes. One could check to see if the 90% confidence interval includes a difference of one. If the interval contains one, the difference is not statistically significant. O No. One can not use a confidence interval to test hypothesis in part (a) because hypothesis tests and confidence intervals are two different things.

The electric cooperative needs to know the mean household usage of electricity by its non commercial customers in kilawatts per day. They would like the estimate to have a maximum era of 0.14 kW. A previous study found that for a average family the variance is 5.29 kW and the mean is 19.9 kW per day. If they are using 80% level of confidence how large of a sample is required to estimate the mean usage of electricity ? Round your answer up to the next integer

C2. Average years of education are reported by social class based on data from the GSS 2018. Mean Standard Deviation 12.19 Lower class 3.08 102 13.16 Working class 2.93 523 14.60 Middle class 2.88 498 15.21 Upper class 3.01 34 Construct the 95% confidence interval for the mean number of years of education а. for lower- and working-class respondents. 1 Construct the 99% confidence interval for the mean number of years of education for lower-class and middle-class respondents. As our confidence in the result increases, how does the size of the confidence interval Change? Explain why this is so.

here are summary statistics for randomly weights of newborn girls. n=203, x=32.4hg s=6.4 hg. Construct a confidence interval estimate of the mean. Use a 90% confidence level. Are these results very different from the confidence interval 30.9 hg< <32.9 hg with only 15 sample values, x=31.9 hg and s=2.2hg?

What z score would be used to calculate the margin of error for a 98% confidence interval for the mean?   2.33 1.75 2.05 correct answer is not given

Here are the summary statistics for randomly selected weights of newborn girls: n =247, x= 32.2 hg, s= 6.8hg . Construct a confidence interval estimate of the mean. Use 90% confidence level. Are these results very different from the confidence interval 31.0 hg < u < 33.2 hg with only 18 sample values, x= 32.1 hg and s=. 2.7 hg ?   What is the confidence interval for the population mean u ? _ hg < u< hg _ (round to one decimal places as needed ?  Are the results between the two confidence intervals very different ? a. Yes, because the confidence interval limits are not similar. b. No. because the confidence interval limits are similarc. Yes, because one confidence interval does not contain the mean of the other confidence intervald.

You may need to use the appropriate appendix table or technology to answer this question. Consider the following results for independent samples taken from two populations. Sample 1 Sample 2 n1 = 400 n2 = 300 p1 = 0.49 p2 = 0.32 (a) What is the point estimate of the difference between the two population proportions? (Use  p1 − p2. )   (b) Develop a 90% confidence interval for the difference between the two population proportions. (Use  p1 − p2.  Round your answer to four decimal places.)  to  (c) Develop a 95% confidence interval for the difference between the two population proportions. (Use  p1 − p2.  Round your answer to four decimal places.)  to

Can someone please help me to solve the following question showing all work.

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