Answer:
x = 6
Step-by-step explanation:
12x+252=324
Subtract 252 from each side
12x+252-252=324-252
12x =72
Divide each side by 12
12x/12 = 72/12
x =6
55 mph minus 40 mph = 15 miles distance for each hour
So 5 hours * 15 = 75 miles difference after 5 hours
The mean is 85.2
Explanation:
Add all the numbers together
98+78+84+75+91=426
Divide the sum by the amount of numbers you added together
426/5= 85.2
Answer:
9.18% probability that a randomly selected person sleeps 6 hours or less
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What is the probability that a randomly selected person sleeps 6 hours or less?
This is the pvalue of Z when X = 6. So



has a pvalue of 0.0918
9.18% probability that a randomly selected person sleeps 6 hours or less
Answer:
84.9
Step-by-step explanation:
R²=2.6x2.6
=6.76
6.76xπ=21.2264
21.2264x4=84.9056
Rounded to 84.9