Answer:
a) z = -1.645
b) z = 0.674
Step-by-step explanation:
We have to find the value of z of a standard normal variable Z that satisfies each of the following conditions.
a) 5% of the observations fall below z
Calculation the value from standard normal z table, we have,
![P(Z](https://tex.z-dn.net/?f=P%28Z%3C-1.645%29%20%3D%200.05%5C%5Cz%20%3D%20-1.645)
b) 25% of the observations fall above z
![P(Z > z) = 0.25\\\Rightarrow P(Zz) = 1 - 0.25 = 0.75](https://tex.z-dn.net/?f=P%28Z%20%3E%20z%29%20%3D%200.25%5C%5C%5CRightarrow%20P%28Z%3Cz%29%20%3D%201%20-%20P%28Z%3Ez%29%20%3D%201%20-%200.25%20%3D%200.75)
Calculation the value from standard normal z table, we have,
![P(Z](https://tex.z-dn.net/?f=P%28Z%3C0.674%29%20%3D%200.75%5C%5Cz%20%3D%200.674)
5/11
((4)^2 - 6) / 3(4)+10
16 - 6 / 12 + 10
10/22 we can simplify this further
10 divided by 2
22 divided by 2
You get 5/11 which is the same as 10/22
Answer:
Richard gets 15 more sweets than Natasha.
Step-by-step explanation:
Given that the ratio of Sarah's sweets is 5 and she has 75 sweets. So firstly, you have to find out how many sweets in a ratio of 1 :
Let ratio be units,
![5 units = 75 sweets](https://tex.z-dn.net/?f=5%20units%20%3D%2075%20sweets)
![1 unit = 75 \div 5](https://tex.z-dn.net/?f=1%20unit%20%3D%2075%20%5Cdiv%205)
![1 unit = 15 sweets](https://tex.z-dn.net/?f=1%20%20unit%20%3D%2015%20sweets)
Now we have to find how many sweets does Natasha and Richard has :
Richard (ratio of 3),
![3 units = 15 \times 3](https://tex.z-dn.net/?f=3%20units%20%3D%2015%20%5Ctimes%203)
![3 units = 45 sweets](https://tex.z-dn.net/?f=3%20units%20%3D%2045%20sweets)
Natasha (ratio of 2),
![2 units = 15 \times 2](https://tex.z-dn.net/?f=2%20units%20%3D%2015%20%5Ctimes%202)
![2 units = 30 sweets](https://tex.z-dn.net/?f=2%20units%20%3D%2030%20%20sweets)
In order to find how many sweets Richard has more than Natasha, you have to substract :
![45 - 30 = 15 sweets](https://tex.z-dn.net/?f=45%20-%2030%20%3D%2015%20sweets)
200÷8= 25
25 hours would have to be worked to pay for insurance.