Given:
a) Greater than z = -1.90.
b) To the right of z = 1.78.
To find:
The per cent of the data.
Step-by-step explanation:
a) The value of z = 1.90 is 0.4713.
The area of the right half part is 0.5.
So, adding these two values we get,
![0.4713+0.5=0.9713](https://img.qammunity.org/2023/formulas/mathematics/college/m08whoclaugfdb8hn6ev3hsuyvrybuo4ny.png)
Converting into the percentages, we get,
![0.9713*100=97.13\%](https://img.qammunity.org/2023/formulas/mathematics/college/60xqhsxuo3skh1tt3tlfh1zrhk2xegyd19.png)
b) The value of z = 1.78 is 0.4625
The area of the right half part is 0.5.
We need to find the area to the right of 1.78.
So, subtracting these two values we get,
![0.5-0.4625=0.0375](https://img.qammunity.org/2023/formulas/mathematics/college/ngdlx9bl8tj55vc2gu6ysi5dtukrsjm3au.png)
Converting into the percentages, we get,
![0.0375*100=3.75\%](https://img.qammunity.org/2023/formulas/mathematics/college/aeiylu5ieyljmc18ix7x4fnecsjbclcbuv.png)
Final answer:
a) The per cent of the data is 97.13%.
b) The per cent of the data is 3.75%.