In: Statistics and Probability
Let x be a random variable representing dividend yield of bank stocks. We may assume that x has a normal distribution with σ = 2.8%. A random sample of 10 bank stocks gave the following yields (in percents). 5.7 4.8 6.0 4.9 4.0 3.4 6.5 7.1 5.3 6.1
The sample mean is x bar = 5.38%. Suppose that for the entire stock market, the mean dividend yield is μ = 5.0%. Do these data indicate that the dividend yield of all bank stocks is higher than 5.0%? Use α = 0.01.
Compute the z value of the sample test statistic.
(Enter a number. Round your answer to two decimal
places.)
Find (or estimate) the P-value. (Enter a number. Round your answer to four decimal places.)
SOLUTION:
From given data,
Let x be a random variable representing dividend yield of bank stocks. We may assume that x has a normal distribution with σ = 2.8%. A random sample of 10 bank stocks gave the following yields (in percents). 5.7 4.8 6.0 4.9 4.0 3.4 6.5 7.1 5.3 6.1. The sample mean is x bar = 5.38%. Suppose that for the entire stock market, the mean dividend yield is μ = 5.0%. Do these data indicate that the dividend yield of all bank stocks is higher than 5.0%? Use α = 0.01.
5.7 | 4.8 | 6.0 | 4.9 | 4.0 | 3.4 | 6.5 | 7.1 | 5.3 | 6.1 |
Where,
= 5.38%
μ = 5.0%
σ = 2.8%
n = 10
Compute the z value of the sample test statistic. (Enter a number. Round your answer to two decimal places.)
the sample test statistic = z = ( -μ ) /(σ / sqrt(n))
z = (5.38 -5.0 ) /(2.8 / sqrt(10))
z = 0.38 / 0.885437
z = 0.42
Find (or estimate) the P-value. (Enter a number. Round your answer to four decimal places.)
As it is right tailed test P value is
P-value = P(z > 0.42) = 1 - P(z < 0.42) = 1-0.66276 = 0.3372
P-value = 0.3372