Answer:
a) The mean is 
b) The standard deviation is 
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 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.
The probability a student selected at random takes at least 55.50 minutes to complete the examination equals 0.6915.
This means that when X = 55.5, Z has a pvalue of 1 - 0.6915 = 0.3085. This means that when 
So




The probability a student selected at random takes no more than 71.52 minutes to complete the examination equals 0.8997.
This means that when X = 71.52, Z has a pvalue of 0.8997. This means that when 
So




Since we also have that 





Question
The mean is 
The standard deviation is 
Answer: 15 feet
Step-by-step explanation:
From the question, we are informed that a diving board is 10 feet above a pool. Since the ladder is 5 feet away from the base of the diving board, to calculate how tall is the ladder is, we subtract -5 from 10. This will be:
= 10 - (-5)
= 10 + 5
= 15 feet
The answer is option C.
The digit 7 would be ten times greater than the digit 7 in number 0.9750 in any number with 7 in the tenths place, for example
0.723
0.7669
0.775
1.7899
Answer:
x-int: (3, 0)
y-int: (0, -1.5)
Step-by-step explanation:
x-intercept is the x-value when y = 0
y-intercept is the y-value when x = 0
Step 1: Find x-intercept
0 = (x - 3)/2
0 = x - 3
x = 3
(3, 0)
Step 2: Find y-intercept
y = (0 - 3)/2
y = -3/2
(0, -1.5)