When analysing normally distributed data, standard deviation can be used in conjunction with the mean in order to calculate data intervals. If = mean, S = standard deviation and x = a value in the data set, then. 1  about 68% of the data lie in the interval: . 2  about 95% of the data lie in the interval: + 2S.
Little gem arborvitae (Thuja occidentals 'Little Gem') is an evergreen shrub that keeps its brilliant color and foliage all year long. Growing 1 to 3 feet tall, little gem has medium texture and a slow growth rate. The dense dwarf shrub has a compact form and globose shape.
Dwarf Alberta spruce trees are classified as evergreen conifers. USDA Plant Hardiness Zones for Dwarf Alberta Spruce Trees: Dwarf Alberta spruce trees can be grown in zones 3-8.Characteristics: Dwarf Alberta spruce trees may eventually reach 12 feet in height, but only over a long period of time (growing just 2-4 inches per year). They have a classic Christmas tree shape.The green needles have a tight, densely-packed growth habit that gives dwarf Alberta spruce trees a fuzzy look.haracteristics: Dwarf Alberta spruce trees may eventually reach 12 feet in height, but only over a long period of time (growing just 2-4 inches per year). They have a classic Christmas tree shape. The green needles have a tight, densely-packed growth habit that gives dwarf Alberta spruce trees a fuzzy look.