Statistics 101 Question?

[bernd]

Please need help with few statistics questions. Thank you

1)The claim is that the proportion of peas with yellow pods is equal to 0.25 (or 25%). The sample statistics from one experiment include 500 peas with 145 of them having yellow pods.
Find the value of the test statistics z using z = (that equation where p-p/sqrt pq/n)

2)The proportion of settled medical malpractice suits is 0.33 Which of the following is a type 1 error?
a) fail to reject the claim that the proportion of settled malpractice suits is 0.33 when the proportion is actually 0.33
b)reject the claim that the proportion of settled malpractice suits is 0.33 when the proportion is actually 0.33
c) fail to reject the claim that the proportion of settled malpractice suits is 0.33 when the proportion is actually different from 0.33
d) reject the claim that the proportion of settled malpractice suits is 0.33 when the proportion is actually different from 0.33

[starling]

1) Observed proportion = O = 145/500 = 0.29
Expected proportion = E = 0.25
p = 0.25
q = 1-p = 1-0.25 = 0.75
n = 500
Standard error of proportion = SEp = sqrt (p*(q/n)
= sqrt (0.25*0.75/500)
0.02
Test statistic = z = (O-E)/SEp
= (0.29-0.25) / 0.02
= + 2

2) Type-I error occurs when a true Ho is rejected.
Therefore answer to the question is CHOICE (b)...