Problem $1.$ What is a digital signal and how does it differ from an analog signal? Give two examples of digital phenomena and two examples of analog phenomena.

Problem $2.$ The figure below shows how binary values are represented as voltage. Why are the input and output HIGH and LOW voltage levels different? What do you think happens if a digital input receives a voltage value between $\mathrm{.}4$ and $\mathrm{.}6$ volts?

Problem $3.$ An analog signal is converted to binary. If the analog signal values range from $0$ to $10$ with a resolution of $0\mathrm{.}25,$ how many bits are needed to represent all the analog values?

Problem $4.$ Convert the following values from the original base to the specified bases.

a$)$ Decimal $345\mathrm{.}625$ to binary, octal, and hexadecimal.

b$)$ Binary $10011010\mathrm{.}01101110$ to decimal, octal, and hexadecimal.

c$)$ Octal $362\mathrm{.}54$ to decimal, binary, and hexadecimal.

d$)$ Hexadecimal A$3\mathrm{.}7$C to decimal, binary, and octal.

All of question $4$ and $2$ please!