o The mean vitamin D ooncertation in healthy European men aged 40 to 79 is 62 nmolIL and Standard deviation is 33 nmoi/L. A group of 40 men at the same age with osteoarthritis was also measured with mean of 52nmoliL. Does the man with osteoarthritis have the same level of vitamin D concertation as the the healthy counterparts? Test at the a = 0.05 level