Question

7.27 Chicken diet and weight, Part I. Chicken farming is a multi-billion dollar industry, and any methods that increase the growth rate of young chicks can reduce consumer costs while increasing company profits, possibly by millions of dollars. An experiment was conducted to measure and compare the effectiveness of various feed supplements on the growth rate of chickens. Newly hatched chicks were randomly allocated into six groups, and each group was given a different feed supplement. Below are some summary statistics from this data set along with box plots showing the distribution of weights by feed type. 400 Weight (in grams) casein horsebean linseed meatmeal soybean sunflower Mean 323.58 160.20 218.75 276.91 246.43 328.92 SD 64.43 38.63 52.24 64.90 54.13 48.84 12 10 12 11 14 12 casein horsebeanlinseed meatmeal soybean sunflower (a) Describe the distributions of weights of chickens that were fed linseed and horsebean. (b) Do these data provide strong evidence that the average weights of chickens that were fed linseed and horsebean are different? Use a 5% significance level. (c) What type of error might we have committed? Explain. (d) Would your conclusion change if we used a 0.01?

Answer 1

from the bo xplot oe chckey thal toeu fed linged and hersebe an t is clear that t Median touigt f tinted fel Cietan is Lephen tra hartebean fed chictor dinteed fed chicken tad greater spread CIR) (1eyh dishmbion fr both ir apprximakely nemal hoideven disho bnhn weizs tor herse bean fed chickuns is slyly mgt UV) ath are relahvehy smic end No outjes Nul Hypothesic inceed horsebeau skenedie Alternate Kypohea Tuoo Samble TOo Adled t-test ingeed t nocan stmble shhishe te ngeed horsebeau Snersca edheseba horsehow 218.75 160.20 (S2-24)(3.62) + 12 3.02 (-1)+ (10-1) = 20 Defincecd1 +("hseea) (fram t-tble) p.walne =.006764 we neject the mull hy hothent Level Since b-vane mchusin Avenage weiu o chickms that went fed linfead pe Aorsebcan is diffenent and it is Commmted au err twe hare rejchd Nul AypoHeris (H) TYPE 1 emor since f we tohn o o1 vane 00676y foY 01 all tonclunen would hot elange, we shil reject H ow So