For those still looking for a solution:

In Java 8 or later, this can be answered trivially using Streams without any loops or additional libraries.

int[] range = IntStream.rangeClosed(1, 10).toArray();

This will produce an array with the integers from 1 to 10.

A more general solution that produces the same result is below. This can be made to produce any sequence by modifying the unary operator.

int[] range = IntStream.iterate(1, n -> n + 1).limit(10).toArray();

Im not going to give you the answer since this sounds like homework but I will help you break it down into manageable chunks.

First, generate 1000000 random numbers between 1 and 100. You were on the right track and combine it with Dawnkeepers hint. int[] randoms = new int[1000000]; is an int array with a size of 1000000. Now iterate over each index and assign it a random number(see above). Now you have an array with a million random numbers. Generating a million randoms can be a lengthy procedure depending on you machine, so yea.

Next, use the Scanner class to get the users input.(pro tip: dont use the same variable name for your scanner as your variable in the for loop lol). Now do an if check to make sure they enter a number between 1 and 100. if(val > 0 && val <= 100). If this passes, move on, else quit or prompt for user to give a new input. Using the scanner is pretty trivial so I wont go into this.

Finally, iterate through your list of randoms and keep a counter of how many numbers less then or equal to x.

int counter = 0;
for(int i = 0; i < randoms.length; i++) {
  //if randoms[i] is less then or equal x, counter++
}

Take that counter and do your math, int final_answer = counter/randoms.length;

That's all that is to it. There are more efficient ways of doing this but I tried to make it simple to follow. If I misread the question, sorry.

The length of an array in Java is immutable. So, you need to copy the desired part into a new array.

Use copyOfRange method from java.util.Arrays class:

int[] newArray = Arrays.copyOfRange(oldArray, startIndex, endIndex);

startIndex is the initial index of the range to be copied, inclusive.
endIndex is the final index of the range to be copied, exclusive. (This index may lie outside the array)

E.g.:

   //index   0   1   2   3   4
int[] arr = {10, 20, 30, 40, 50};
Arrays.copyOfRange(arr, 0, 2);          // returns {10, 20}
Arrays.copyOfRange(arr, 1, 4);          // returns {20, 30, 40}
Arrays.copyOfRange(arr, 2, arr.length); // returns {30, 40, 50} (length = 5)