The histogram shows the numbers of people who volunteered for community service and the number of hours they worked. Use the his
togram to answer the question.
How many volunteers worked more than 15 hours?
A.
25
B.
50
C.
60
D.
75
How many volunteers worked more than 15 hours?
A.
25
B.
50
C.
60
D.
75
2 answers:
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Answer:
95% confidence interval for the difference between the proportions of males and females who have the blood disorder is [-0.064 , 0.014].
Step-by-step explanation:
We are given that a certain geneticist is interested in the proportion of males and females in the population who have a minor blood disorder.
A random sample of 1000 males, 250 are found to be afflicted, whereas 275 of 1000 females tested appear to have the disorder.
Firstly, the pivotal quantity for 95% confidence interval for the difference between population proportion is given by;
P.Q. = ~ N(0,1)
where, = sample proportion of males having blood disorder=
= 0.25
= sample proportion of females having blood disorder =
= 0.275
= sample of males = 1000
= sample of females = 1000
= population proportion of males having blood disorder
= population proportion of females having blood disorder
<em>Here for constructing 95% confidence interval we have used Two-sample z proportion statistics.</em>
<u>So, 95% confidence interval for the difference between the population proportions, </u><u>(</u><u>)</u><u> is ;</u>
P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5% level
of significance are -1.96 & 1.96}
P(-1.96 < < 1.96) = 0.95
P( <
<
) = 0.95
P( < (
) <
) = 0.95
<u>95% confidence interval for</u> () =
[,
]
= [ ,
]
= [-0.064 , 0.014]
Therefore, 95% confidence interval for the difference between the proportions of males and females who have the blood disorder is [-0.064 , 0.014].