Given data:
Mean: 84 lb
Standard deviation: 12lb
Find % of hippos born weighing 25 poind or less.
1. Find the z-score corresponding to x=25:
![\begin{gathered} z=(x-\mu)/(\sigma) \\ \\ z=(25-84)/(12) \\ \\ z=-(59)/(12) \\ \\ z=-4.92 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/px5y4tyh21ihb949lhree4c5lwf7ljvtd9.png)
2. Use a z-table to find the probability of x less or equal to 25 (z-score -4.92):
For a z-score of -3.50 or less the corresponding value is 0.0001
![P(x\leq25)=0.0001](https://img.qammunity.org/2023/formulas/mathematics/college/h9bduvjnalpwnm3rbz8fqqzpwtk1f30hg6.png)
3. Multiply by 100 the value you get in step 2 to get the percentage:
![0.0001*100=0.01](https://img.qammunity.org/2023/formulas/mathematics/college/45jiz4vwhqpuu4f2ethq4sqp1qkskycqdt.png)
Then, the percentaje of hippos born weighing 25 poind or less is 0.01%