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
The number is multiplied by 3 every time
and next three terms are 1/324, 1/972 and 1/2916
good luck
Plan 1 because she spends 435.88 more if she goes with plan 2
The slope is 10. For every 1 increase in x, y increases by 10.