Question

18

The IQ scores for a random sample of subjects with mediu lead levels in their blood and another random sample of subjects with high lead levels in their blood are given below. Use a 0.05 significance Medium Lead Level Hich with medium lead levels have full Q scores with a higher median that the median full IQ score for subjects with high lead levels. Does lead level appear to affect full IQ scores? EEB Click the icon to view the data table. First deline the null and alternative hypotheses Ho: H1 Identify the test statistic. 85 79 12 90 103 (Round to two decimal places as needed.) Calculate the P-value. P-value- Round to four decimal places as needed.) Choose the correct answer below. O A. Fail to reject H0 There is su cient evidence to support the claim that sub ects with mediu 15 16 17 岡回 lead ieve have O B Re ect H0 There is su scores with a higher median than subjects with high lead levels. Reject Ho T ere ls insufficient evidence o support the calm that subiects with medium lead levels have u Id scores with a higher median than subjects wth high lead levels. ient evidence to support the claim that subjects with medium lead level have tull IQ full IQ scores with a higher median than subjects with high lead levels. Fail to re ect Ho There s insufficient evidence o support the claim that subiects with medium lead levels have full Q scores with a higher median than subjects with high lead levels 。C. O D Does lead level appear to affect full IQ scores? A. It does not appear that lead level affects full IQ scores because there is insufficient evidence to support the claim. It appears that lead level affects full IQ scores because there is insufficient evidence to support the claim. в. O C. It appears that lead level affects full IQ scores because there is sufficient evidence to support the claim.

Answer 1

wilxocon rank sum test

sample 1	sample 2	rank for sample 1	rank for sample 2
85	71	20.5	9.5
79	74	15.5	11
89	92	23	25
62	60	3	1.5
76	83	12	18
79	60	15.5	1.5
83	67	18	7
98	95	28	26
77	83	13.5	18
71	77	9.5	13.5
90	103	24	29
85	86	20.5	22
70	64	8	5.5
96	63	27	4
64	107	5.5	30

H0: The two samples come from population with equal medians.

H1: The medium lead level population has a higher median IQ than the high lead level population.

sample 1      
sample size ,    n1 =    15
sum of ranks ,    R1 =    243.5
      
sample 2      
sample size ,    n2 =    15
sum of ranks ,   R2 =    221.5
      
R=sum of ranks for smaller sample size =       243.5
      
mean ,µ =    n1(n1+n2+1)/2 =    232.5
      
std dev,σ =    √(n1*n2*(n1+n2+1)/12) =   24.1091
      
Z-stat =    (R - µ)/σ =    0.47

P-value =        0.6759

P-value>α , fail to reject null hypothesis

fail to rejejct Ho, There is insufficient evidence to support the claim that subject with median lead levels have full IQ score with a higher median than subjects with high lead levels

It doesn't appear that lead level effects full IQ scores as there is insufficient evidence.to support the claim