Measurements in lumens per square foot are made for testing the uniformity of lighting using four lighting systems (X1 to X4). Using a 5% level of significance and the following data, determine whether or not the four lighting systems provide equal uniformity in lighting intensity:

X1 56 63 49 58 65 X2 47 52 48 56 51 X3 62 65 56 59 60 X4 48 62 55 47 64