Let the amount Tom does = x
Then Larissa’s time would be 3x( 3 times the amount of Tom)
And Neal would also be 3x
The total of the 3 is 84 hours so as an equation you have:
X + 3x + 3x = 84
Combine like terms
7x = 84
Divide both sides by 7
X = 84/7
X = 12 hours
Tom = x, so Tom exercised for 12 hours.
Answer:
The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.
Step-by-step explanation:
Problems of normally distributed samples are 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.
In this problem, we have that:

What is the reading speed of a sixth-grader whose reading speed is at the 90th percentile
This is the value of X when Z has a pvalue of 0.9. So it is X when Z = 1.28.




The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.
Answer:
1 5/6, 2 1/3, 2 3/5
Step-by-step explanation:D
Answer:
Option 1, 2, and 4 are correct. Option 3 is incorrect.