shes to determine if there is any difference between the two brands in the mean lifetime of the bulbs used. Of the light buibs used the projectórs. The purchasing manager has narrowed down the choice of projector to two brands, Infocus and Proxima, an ne purchasing manager obtained eight projectors of each brand for testing over the last several academic terms. The number of hours the bulbs lasted on ea f the eight projectors is given in the table. Lifetimes of light bulbs (hours) Infocus 745, 955, 1085, 756, 901, 839, 858, 931 Proxima 1012, 988, 957, 920, 878, 1130, 657, 743 Send data to calculator Assume that the two populations of lifetimes are normally distributed and that the population variances are equal. Can we conclude, at the 0.01 level of significance, that H, the mean lifetime of light bulbs in Infocus projectors, differs from H, the mean lifetime of light bulbs in Proxima projectors? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.) (a) State the null hypothesis Ho and the alternative hypothesis H,. H. H, : μ1- μ2 H, : u u2 (b) Determine the type of test statistic to use. Degrees of freedom: O=0 OSO (c) Find the value of the test statistic. (Round to three or more decimal places.) O

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Degrees of freedom? Also am I doing everything else correctly 

A purchasing manager for a large university is investigating which brand of LCD projector to purchase to equip their classrooms. Of major concern is the
longevity of the light bulbs used in the projectors. The purchasing manager has narrowed down the choice of projector to two brands, Infocus and Proxima, a
wishes to determine
there is any difference between the two brands in the mean lifetime of the bulbs used.
The purchasing manager obtained eight projectors of each brand for testing over the last several academic terms. The number of hours the bulbs lasted on ea-
of the eight projectors is given in the table.
Lifetimes of light bulbs (hours)
Infocus 745, 955, 1085, 756, 901, 839, 858, 931
Proxima 1012, 988, 957, 920, 878, 1130, 657, 743
Send data to calculator
Assume that the two populations of lifetimes are normally distributed and that the population variances are equal.
Can we conclude, at the 0.01 level of significance, that H, the mean lifetime of light bulbs in Infocus projectors, differs from H, the mean lifetime of light bulbs
in Proxima projectors?
Perform a two-tailed test. Then complete the parts below.
Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of
formulas.)
(a) State the null hypothesis H, and the alternative hypothesis H,.
H, : u1 = p2
H, p2
(b) Determine the type of test statistic to use.
t
Degrees of freedom:
O=0
OSO
(c) Find the value of the test statistic. (Round to three or more decimal places.)
O<O
0.403
(d) Find the p-value. (Round to three or more decimal places.)
0.6929
(e) Can we conclude that H, the mean lifetime of light bulbs in Infocus
projectors, differs from H, the mean lifetime of light bulbs in Proxima
projectors?
O Yes O No
olo
Transcribed Image Text:A purchasing manager for a large university is investigating which brand of LCD projector to purchase to equip their classrooms. Of major concern is the longevity of the light bulbs used in the projectors. The purchasing manager has narrowed down the choice of projector to two brands, Infocus and Proxima, a wishes to determine there is any difference between the two brands in the mean lifetime of the bulbs used. The purchasing manager obtained eight projectors of each brand for testing over the last several academic terms. The number of hours the bulbs lasted on ea- of the eight projectors is given in the table. Lifetimes of light bulbs (hours) Infocus 745, 955, 1085, 756, 901, 839, 858, 931 Proxima 1012, 988, 957, 920, 878, 1130, 657, 743 Send data to calculator Assume that the two populations of lifetimes are normally distributed and that the population variances are equal. Can we conclude, at the 0.01 level of significance, that H, the mean lifetime of light bulbs in Infocus projectors, differs from H, the mean lifetime of light bulbs in Proxima projectors? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H,. H, : u1 = p2 H, p2 (b) Determine the type of test statistic to use. t Degrees of freedom: O=0 OSO (c) Find the value of the test statistic. (Round to three or more decimal places.) O<O 0.403 (d) Find the p-value. (Round to three or more decimal places.) 0.6929 (e) Can we conclude that H, the mean lifetime of light bulbs in Infocus projectors, differs from H, the mean lifetime of light bulbs in Proxima projectors? O Yes O No olo
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