What is the probability that a randomly selected pregnancy lasts more than 274 days? - pregnancy more condition_symptoms hemorrhoids
Let X be the length of pregnancy in days. Suppose that X is usually with an average of 266 days and a standard deviation is divided by 16 days.
a. What is the probability that a randomly chosen pregnancy lasts for more than 274 days?
b. Suppose we have a random sample of 25 pregnant women. Is it more or less likely than their response to (a) an example of the average duration of pregnancy of more than 274 days can be seen? Tip (find P (X-bar> 274) and compare with (a)
Saturday, January 16, 2010
Pregnancy More Condition_symptoms Hemorrhoids What Is The Probability That A Randomly Selected Pregnancy Lasts More Than 274 Days?
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a)
x = duration of the pregnancy
standardized as z = x (x-mean) / SD
μ = 266
σ = 16
P (x> 274) = P (z> (274-266) / 16)
= P (Z> 0.5) = 0.3085 (from the table of normal distribution)
b)
z = (x-mean) SD / sqrt (n)
They are divided by smaller numbers, so that its z becomes larger than reaction (a);
Therefore, the probability of a value> 274 smaller.
The mean μ = 266
The standard deviation σ = 16
Standard error σ / √ n = 16 / √ 25 = 3.2
P (x> 274) = P (z> (274-266) / 3.2)
= P (Z> 2.5) = 0.0062 (from tables of normal distribution)
less likely
0.0062 to 0.3085
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