Question

1- For the following distribution of systolic blood pressure 115,123,115,129,121,123,129,123,141,135,121,121,119,117,128,131,133,116 ,116,119 the Interquartile range is

A. 5

B. 7

C. 9

D. 11

2- The table below shows the result of a survey of 200 cyclists and their preferred routes.

	lake path	hilly path	wooded path	Total
Female	45	38	27	110
Male	26	52	12	90
total	71	90	39	200

A. If one cyclist is randomly selected. Find the probability that the cyclist does not prefer a hilly path.

B. If one cyclist is randomly selected. Find the probably that the cyclist is either male or prefers wooded path.

C. Find the probability of randomly selecting a female, given that the female prefers lake Path.

3- A researcher claims that 19% of US adults are smokers. In a random sample of 250 US adults 55 were found to be smokers. Use a 0.05 significance level to test the researcher’s claim

Answer 1

Ans:

1)Sorted data:

115,115,116,116,117,119,119,121,121,121,123,123,123,128,129,129,131,133,135,141

Median=122
Minimum=115
Maximum=141
First quartile: 118
Third quartile: 129
Interquartile Range=129-118=11

Option D is correct(11)

2)

a)P(not prefer hilly path)=(71+39)/200=110/200=0.55

b)P(male or wooden path)=(90/200)+(39/200)-(12/200)=0.585

c)P(female/lake path)=45/71=0.634

3)

sample proportion=55/250=0.22

Test statistic:

z=(0.22-0.19)/SQRT(0.19*(1-0.19)/250)

z=1.209

p-value(2 tailed)=2*P(z>1.209)=0.2266

Fail to reject H0,as p-value>0.05

There is not sufficient evidence to reject the claim .