Question

Timed Test Thistest has a time of 2 hours and 30 minutes. This test will save and submit automatically when the time expres. Warnings appear when half the time 5 minutes 1 minute and seconds reman Multiple Anemos Not allowed. This can only be taken once Force Completion Once started this test must be completed in one Do not be the before Save and Suit Your answers are saved automatically Remaining Time: 2 hours, 25 minutes 52 seconds Question Completion Status: Moving to another question will save this response Question of 36 Question 1 2.TTTTT Construct the indicated confidence interval for the difference between the two population means. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal A pi cture wished to compare they s t ypes of Independent simple de les fl o w surfaces. The drying time in hun were the y a re as follows Type A Type B Xy - 757 hes 643 45hes -5.1 hes ny - 11 Contacta con nerval for the direct e d 592 hrs < < 16 8 hes 60 9 16.72 hrs 5.78hrs 17.0hrs on 10 Moving to another question will MacBook Air HJ KIL

Answer 1

1)

We know that the 98% confidence interval for difference between population means is given by:

$[(\overline{x_{1}}-\overline{x_{2}})\pm t_{n_{1}+n_{2}-2}(0.02/2)\sqrt{\frac{s_{1}^{2}}{n_{1}}+\frac{s_{2}^{2}}{n_{2}}}]$

$[(75.7-64.3)\pm t_{11+9-2}(0.02/2)\sqrt{\frac{4.5^{2}}{11}+\frac{5.1^{2}}{9}}]$

$[(75.7-64.3)\pm t_{18}(0.01)\sqrt{\frac{4.5^{2}}{11}+\frac{5.1^{2}}{9}}]$

$[(75.7-64.3)\pm (2.552)\sqrt{\frac{4.5^{2}}{11}+\frac{5.1^{2}}{9}}]$

$[11.4\pm 5.5508]$

Hence 4th option.