Question

Given the following information, use Excel’s Regression tool and scatter plot tool to: (No need to show the regression and scatter plot just answer the questions.)
(c) What is the 95% prediction interval for the true overhead when the number of units produced is 1,000?

Month	Units produced	Manuf. Overhead
1	500	131,000
2	600	135,000
3	400	104,000
4	300	76,000
5	800	186,000
6	900	190,100
7	600	150,000
8	400	98,000
9	300	78,000
10	200	60,000
11	400	108,000
12	600	152,000
13	700	158,000
14	500	134,380
15	300	86,000
16	200	60,000

Answer 1

Regression output				confidence interval
variables	coefficients	std. error	t (df=14)	p-value	95% lower	95% upper	std. coeff.
Intercept	23,643.2590	4,716.8717	5.012	.0002	13,526.5753	33,759.9426	0.000
Units produced	198.4660	9.0463	21.939	3.06E-12	179.0636	217.8683	0.986
Predicted values for: Manuf. Overhead
		95% Confidence Interval	95% Prediction Interval
Units produced	Predicted	lower	upper	lower	upper	Leverage
1,000	2,22,109.214	2,11,317.358	2,32,901.070	2,03,160.890	2,41,057.539	0.480

Predictive Confidence Interval of
Ŷ = 23643.259 + 198.466X
Ŷ = 222109.259

95% Predictive confidence interval is ( 203160.890 < < 241057.539 ).