A random sample of 36 observations is to be taken from a normal distribution with variance 100. In the past, the distribution has a mean of 83.0, but it is believed that recently the mean may have changed. Using a 5% significance level, determine an appropriate test of the null hypothesis that the mean is 83.0. When the sample is actually taken, it is found to have a mean of 86.2. Does this provide significant evidence against null hypothesis?