HW11_skeleton

10.2

• 1. statistically significant
• 2. true
• 3. false
• 4. 2.33
• 5. -1.28
• 6. 1.96

7.)

a) z0=2.315>z0.05=1.645 - reject null
  
b) .0104<.05 -reject null

11.)

a) z0=-1.49, -z.025=-1.96, z=.025=1.96 fail to reject null
  x
b) p-val=.1362 > sig.=.05. we do not reject the null (not enough evidence)

 

17. z0=.65<z.01=2.326 fail to reject null p-val=.2578>a=.01 fail to reject null there isnt evidence that suggests that more that 1.9% of lipitor users experience flu like symptoms

18. Z0=.6302<Z.01=2.33 fail to reject there isn’t enough evidence to support the manufacturer’s claim

 

10.3

1.)

a) 2.602
  
b) -.1729
  
c) +/- 2.179

12.)

a) Ho: mu=63.7
   
   H1:mu>63.7
  
b) if the p value is .35 this means theres a .35 probability of getting a sample mean of 63.9 in. or higher from a pop w/ a mean of 63.7. 
  
c) the p-value is high so we fail to reject the statement in the null hypothesis. There isn't sufficient evidence to conclude that the mean height of women today is more than in 1990.

13.)

a) Ho:mu=22

   H1:mu>22
  
b) the sample is random with a large sample size (200≥30) We can assume that the sample is small relative to the pop so the scores are independent.
  
c) classical: t0=2.176 > t.05=1.66 - reject the null
  

d) There is enough evidence to conclude that students who complete the core curriculum score above 22 on math portion of ACT

14.)

a) Ho:mu=501

   H1: mu<501

b) the sample is random with a large sample size (100≥30) We can assume that the sample is small relative to the pop so the scores are independent.
  
c) classical: t0=-1.38<-1.290 - reject the null

d) There is enough evidence to suggest that those who speak 2 languages score lower on the SAT critical reading exam

15. t0= -4.553 < -t.01=-2.718 - reject the null. Sufficient evidence to conclude that the mean hippocampal volume in alcoholic adolescents is less than the normal mean vol. of 9.02 cm3.