Answer:
The average of all textbooks is $38.60.
Step-by-step explanation:
Here's why to calculate average we do sum of all numbers divided by the number of numbers, for example if we average 2 and 3, we do 2+3 divided by 2. Which happens to be 2.5. Now for this problem we divide the sum by 3.
Therefore getting our answer of $38.60.
If this helps hit the thank button!
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)
If the ratio is 90:3 and there are 4 groups of 3 in 12, then the ratio would then be 450:12, leaving you with 450 as the answer. Hope I helped
187,400 or 187,200 I'm sorry I'm bad at these questions
2 minutes and $7.50 would be the answer please put me down as brainliest