Answer:A ratio compares two numbers or two quantities that are measured with the same unit. The ratio of a to b is written a to b,ab,ora:b. ... When a ratio is written in fraction form, the fraction should be simplified. If it is an improper fraction, we do not change it to a mixed number.
Step-by-step explanation:
A ratio compares two numbers or two quantities that are measured with the same unit. The ratio of a to b is written a to b,ab,ora:b. ... When a ratio is written in fraction form, the fraction should be simplified. If it is an improper fraction, we do not change it to a mixed number.
Answer:
21
Step-by-step explanation:
He will guess correctly 25% of the time.
He has 84 questions
25% of 84
.25 * 84
21
We should expect that he will get 21 questions correct
Answer:
P(X > 25) = 0.69
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 sale prices for a particular car are normally distributed with a mean and standard deviation of 26 thousand dollars and 2 thousand dollars, respectively.
This means that 
Find P(X>25)
This is 1 subtracted by the pvalue of Z when X = 25. So



has a pvalue of 0.31
1 - 0.31 = 0.69.
So
P(X > 25) = 0.69