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PlayStation 3's initial production cost is estimated by iSuppli to have been US$805.85 for the 20 GB model and US$840.35 for the 60 GB model. However, they were priced at US$499 and US$599 respectively, meaning that units may have been sold at an estimated loss of $306 or $241 depending on model, if the cost estimates were correct, and thus may have contributed to Sony's games division posting an operating loss of ¥232.3 billion (US$1.97 billion) in the fiscal year ending March 2007. In April 2007, soon after these results were published, Ken Kutaragi, President of Sony Computer Entertainment, announced plans to retire. Various news agencies, including The Times and The Wall Street Journal reported that this was due to poor sales, while SCEI maintains that Kutaragi had been planning his retirement for six months prior to the announcement.

What was the name of Sony's President who announced his retirement amid rumors in April 2007?
Ken Kutaragi