Describe how to use a tens fact to find the difference for 15-8.
1 answer:
You might be interested in
We have been given that the lifespans of lions in a particular zoo are normally distributed. The average lion lives 12.5 years; the standard deviation is 2.4 years. We are asked to find the probability of a lion living longer than 10.1 years using empirical rule.
First of all, we will find the z-score corresponding to sample score 10.1.
, where,
z = z-score,
x = Random sample score,
= Mean
= Standard deviation.
Since z-score of 10.1 is . Now we need to find area under curve that is below one standard deviation from mean.
We know that approximately 68% of data points lie between one standard deviation from mean.
We also know that 50% of data points are above mean and 50% of data points are below mean.
To find the probability of a data point with z-score , we will subtract half of 68% from 50%.
Therefore, the probability of a lion living longer than 10.1 years is approximately 16%.
Given:
A solution of 60% fertilizer is to be mixed with a solution of 21% fertilizer to form 234 liters of a 43% solution.
To find:
The quantity of the 60% solution in the mixture.
Solution:
Let x be the quantity of the 60% solution and y be the quantity of the 21% solution.
Quantity of mixture is 234. So,
...(i)
The mixture has 43% fertilizer. So,
Multiply both sides by 100.
...(ii)
Using (i) and (ii), we get
Divide both sides by -39.
Putting this value in (i), we get
Therefore, 132 liters of the 60% solution must be used.