A study conducted at Virginia Commonwealth University in Richmond indicates that many older individuals can shed insomnia through psychological training. A total of 75 insomnia sufferers averaging age 67 years old completed eight weekly sessions of cognitive-behavior therapy. After the therapy, 28 participants enjoyed a substantially better night’s sleep. Calculate the sample proportion of insomnia sufferers who did not enjoy a better night’s sleep after the therapy. Round your answer to three decimal places, if necessary.