A two sample t test H0 no difference between ideology of parties Ha difference

# A two sample t test h0 no difference between ideology

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A two sample t-test H0 = no difference between ideology of parties Ha = difference between etc. T= -0.46 P = 0.32 PVDA Mean = 3.63 N = 222 St. dev = 1.21 SE of mean = 0.08 SP Mean = 3.69 N = 249 St. dev = 1.60 SE = 0.10

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Today’s lecture Many studies collect data on categorical variables , such as sex, nationality, political orientation, etc. The parameters of interest in these settings are population proportions . The statistic used to estimate a population proportion is the sample proportion .
Sampling distribution of a sample proportion The sampling distribution of a sample proportion is approximately normal (normal approximation of a binomial distribution) when the sample size is large enough

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Conditions for inference on p Assumptions: 1. The data used for the estimate are an SRS from the population studied. 2. The population is at least 10 times as large as the sample used for inference. This ensures that the standard deviation of is close to 3. The sample size n is large enough that the sampling distribution can be approximated with a normal distribution. How large a sample size is required depends in part on the value of p and the test conducted. Otherwise, rely on the binomial distribution. 1 p( p) n. p ˆ