Question

A CI is desired for the true average stray-load loss (watts) for a certain type of induction motor when the line current is held at 10 amps for a speed of 1500 rpm. Assume that stray- load loss is normally distributed with a = 2.3. (Round your answers to two decimal places.) (a) Compute a 95% CI for when n25 and x = 53.7. watts (b) Compute a 95% CI for when 100 and 53.7. watts (c) Compute a 99% CI for when n100 and X - 53.7. watts (d) Compute an 82% CI for when n100 and X - 53.7. watts (e) How large must n be if the width of the 99% interval for is to be 1.0? (Round your answer up to the nearest whole number.) a nithe annunriate tahle in the Annandi nf Tables to answer this question.

Answer 1

a) The 957. ca is - R = Zonos (on) Сле - 1.96 get! Zara Zo.org from Z-table So required CI is : 2.3 53.7 + 1.96 Com V25 53.7+ 0.9016 (52.7984, 54.6016) - ( 1 52.80 54.6 watts. b) for n=100 (I 53.7 + Voo 53.7 + 0.4508 - (53.2942 54.1508 53.29, 54.15

ggy 2.58 2419 Zo.oog x Zones ( - ) So, 53.7† 2.58( 2.3 Too 53.7 0.5934 53.1066, 54.2934 watts. (153.11],[54.29] 82%. (:- 2012 + Z0.18 = Zo.og - 1.34 2 so X + 1.34 (6) 53.7+ 1.34 per me 53.7 ± 0.3082 (1 53.3918 54.0082) 2 2 (153.39 154.01 e) for width = 24 Zija ( ) = - 2x (2-58) (2.3) - 1 > n = (2*2.58X2-3)? - n = 140.54g 141