Casio ALGEBRA FX2.0 Advanced Statistics Examples 2 - Manual (Page 10)

35
examples
○ ○ ○ ○ ○
Example A paint manufacture wants to determine the average drying time of a
new interior wall paint. If for 12 test areas of equal size he obtained a
mean drying time of 66.3 minutes and a standard deviation of 8.4
minutes, construct a 95% confidence interval for the population mean
µ
.
Procedure
1 m STAT2
2 4 (INTR) c (T) b (1-Smpl)
3 2 (VAR) c
.jf w
gg.d w
i.e w
bc w
1 (None) c
4 1 (CALC)
Result Screen
Thus, the 95% confidence interval for
µ
becomes 61.0<
µ
<71.6 .