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# s2 critcal region question watch

1. A seed merchant usually keeps her stock in carefully monitored conditions. After the christmas holidays one year she discovered that the monitoring system had broken down and there was a danger the seed might have been damaged by frost. She decided to check and sample of 10 seeds to see if the proportion p that germinated had been reduced from the usual value of 0.85. Find the critical region for a one tailed test using 5% sig level?

How would you work this out. I was thinking that it was binomial and i should change the probability to 0.15 . Where should i go from here do i do p(x<=c1)<=0.05 ?
2. Not quite sure of what you mean by x<=c1. You want to find if the proportion of germinated seeds has shrunk: or, yes, if the number of failed seeds has grown. So your two hypotheses are effectively p=0.15, p>0.15. So you do an upper, one tailed test. I think... seems okay anyway. Essentially what it's asking you is: what values are less than 5% likely, if p=0.15, in the upper part of the distribution? Does that refresh your method memory?

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Updated: January 18, 2010
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