Answer: 0.8413
Step-by-step explanation:
Given : Henry has collected data to find that the typing speeds for the students in a typing class has a normal distribution.
Mean :
Standard deviation : 
Let x be the random variable that represents the typing speeds for the students.
The z-score :-

For x= 51

Using the standard normal distribution table ,the probability that a randomly selected student has a typing speed of less than 51 words per minute :-

Hence, the probability that a randomly selected student has a typing speed of less than 51 words per minute = 0.8413
Answer:
0.012t + 28 = 30
Step-by-step explanation:
The depth starts at 28 meters. The amount of increase in t minutes will be 0.012t, so the total depth after t minutes is ...
0.012t +28
We want to find when that is equal to 30, so the appropriate equation is ...
0.012t +28 = 30
Answer:
$ 20
Step-by-step explanation:
Given that,
No. of notes Joe has = 4
The total value of the notes = $ 75
From the given notes, 4 notes that can make the sum of 75 would be
$ 50 note + $ 10 + $ 10 note + $ 5
= 50 * 1 + 10 * 1 + 10 * 1 + 5 * 1
= $ 75
Thus, the note that would not be included in the total value would $20 note as if we add it either the sum would be greater or lesser with four notes in combination.