Answer:
A) 0.0107
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Mean of 440 seconds and a standard deviation of 40 seconds.
This means that 
Find the probability that a randomly selected boy in secondary school can run the mile in less than 348 seconds.
This is the p-value of Z when X = 348. So



has a p-value of 0.0107, and thus, the correct answer is given by option A.
Answer:
23.6 (approximate value)
Step-by-step explanation:
- a*a+b*b=c*c Pythagorean thereom
- (21.5)^2 + b*b = (31.9)^2
- b*b= 1017.61 - 462.25
- √b*b= √555.36
- b=23.6(approximate value)
Slope = 75
Y-intercept = 150
If you are asking if your work is good,thn yes,you are right