Question

6. The data show the time intervals after an eruption​ (to the next​ eruption) of a certain geyser. Find the regression​ equation, letting the first variable be the independent​ (x) variable. Find the best predicted time of the interval after an eruption given that the current eruption has a height of 111 feet. Use a significance level of 0.05.

Height (ft)           Interval after (min)

136        80

144        76

140        78

151        94

115        69

129        75

160        93

123        72

What is the regression​ equation?

Ŷ=____+____x

(Round to two decimal places as​ needed.)

What is the best predicted time for the interval after an eruption that is 127 feet​ high?

The best predicted interval time for an eruption that is 127 feet high is _____minutes.

​(Round to one decimal place as​ needed.)

Answer 1

Ans:

	Height(x)	interval,y	xy	x^2
1	136	80	10880	18496
2	144	76	10944	20736
3	140	78	10920	19600
4	151	94	14194	22801
5	115	69	7935	13225
6	129	75	9675	16641
7	160	93	14880	25600
8	123	72	8856	15129
Total	1098	637	88284	152228

slope,b=(8*88284-1098*637)/(8*152228-1098^2)=0.56

y-intercept,a=(637-0.5602*1098)/8=2.73

Regression equation:

y'=2.73+0.56 x

when x=127

y'=2.73+0.56*127=73.9 minutes