Please help me find the sample size.

In 2009, the FDA Oncology Drug Advisory Committee (ODAC) recommended that the drug Avastin be approved for use in glioblastoma, a form of brain cancer. Tumor shrinkage after taking a drug is called a response. Out of 85 patients in a study to investigate the effectiveness of Avastin, 24 exhibited a response. Historically, response probabilities for brain cancer drugs were approximately 0.05.

1. Suppose we wanted to estimate the proportion of patients given Avastin who experience tumor shrinkage with a 95% CI with a margin of error no larger than 6%, i.e., m= .03. What sample size is required?

I calculated: n = 1.92²(0.5)(1 - 0.5) / (0.03) ² = 1067.11 = 1068 subjects

Is this correct?

Thank you!