Step-by-step explanation:
perpendicular slope is negative reciprocal. -1/-1 = 1
y - 4 = x +3
y = x + 7
y=-2
Step-by-step explanation:
if line has zero slope (b) it means that b is undefined.
if x=0 y=-2 because line has no slope. so b=-2
y=-2
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:
40/20, 40:20, 40 to 20
Step-by-step explanation:
20min/1hr
40min/1hr
Question order asks ratio from outside time to inside time so the 40 would come first. also, all the above are correct. You can write a ratio as a fraction, with a colon, or with the word to.