Answer:
5, 7
Explanation:
The mode of the numbers is 5, which means that 5 should be the most common card (highest frequency). Therefore the cards should have at least one more 5 among them.
Considering that 5 is one of the hidden cards and x is the other,
• Using the equation for the mean:
![mean = (sum \space\ \space\ of \space\ \space\ numbers)/(number \space\ \space\ of \space\ \space\ numbers)](https://img.qammunity.org/2023/formulas/mathematics/college/6ysmyvz2pda04mlrtqk8rc9dc6laepqcp0.png)
![6 = (4+5+ 9 + 5 + x)/(5)](https://img.qammunity.org/2023/formulas/mathematics/college/z2ah16xvdzepuoootnzht633wxx9lp2xp8.png)
⇒
![30=23 + x](https://img.qammunity.org/2023/formulas/mathematics/college/2kmfwklx6pyyhovspnkr6cyhsevtj8uy0h.png)
⇒
![x = 7](https://img.qammunity.org/2023/formulas/mathematics/high-school/df2my1cgsrcwodwa2m7ah6g04ugejfdfov.png)
This means 5 and 7 are the hidden cards.