Because 4.7 is the "abbreviation" for 4.70 also 4.7 is the simplified version of 4.70 kind of like a fraction you 4 70/100 simplified is 4 7/10 or 4.7.
147 63 82 101 155 160 175 92 116 138 74 93 110 162 154 105 97
The frequency to her third group is 80 - 99.
Step-by-step answer:
standard deviation (sigma) = 12 inches
mean (mu) = 90 inches.
For 36 years, the standard error of the mean is
e = sigma / sqrt(n) = 12" / sqrt(36) = 2".
Deviation from the mean
= 92.8 -90 = 2.8
Since the standard error of the mean follows the normal distribution, we have
Z=(92.8-90)/2 = 1.4
Looking up the normal distribution tables, or check R, we find
P(Z>1.4) = 1-P(Z<1.4) = 1-0.9192433 = 0.08075666
Answer: P(snowfall>92.8) = 0.0808 (to four decimal places)
