Annie bought a brand new car for $32,000. The car is now worth $21,000.
2 answers:
You might be interested in
Answer:
a) 35, b) 25, c) 60
Step-by-step explanation:
The number of girls is 10 more than the number of boys, so it's a good thing to choose a variable to represent the number of boys.
Number of boys: b
Number of girls: b + 10
Ratio of girls:boys is 7:5, so
"Cross multiply" to get
There are 25 boys. There are 10 more girls, so the number of girls is 35, and the total number of students is 60.
That's a packed classroom!
Answer:
The child's reading level is at the 3.4th percentile.
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 z-score 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 p-value, we get the probability that the value of the measure is greater than X.
You do some research and determine that the reading rates for their grade level are normally distributed with a mean of 90 words per minute and a standard deviation of 24 words per minute.
This means that
You find an individual that reads 46.4 word per minute. At what percentile is the child's reading level?
The percentile is the p-value of Z when X = 46.4, multiplied by 100. So
has a p-value of 0.034.
0.034*100 = 3.4
The child's reading level is at the 3.4th percentile.