To find the approximate number of visitors to the museum in 1990, we first need to determine the value of \( x \) for that year. Since \( x = 0 \) represents 1970 and \( x = 5 \) represents 1975, we can calculate \( x \) for 1990.
We see that 1990 is 20 years after 1970, so:
- \( 1990 - 1970 = 20 \)
- In 5 years (from 1970 to 1975), \( x \) increases by 5. So:
- From 1970 to 1990 (20 years), we can scale appropriately:
\[ x = 20 / 5 \times 5 = 20 \] Thus, \( x \) will be 20 (or simply counting, from 1970 to 1990: include 1970 as 0, 1975 as 5, 1980 as 10, 1985 as 15, and 1990 as 20).
Next, we plug \( x = 20 \) into the equation \( y = 1.31x + 3.19 \):
\[ y = 1.31(20) + 3.19 \]
Calculating this gives:
\[ y = 26.2 + 3.19 = 29.39 \]
Thus, the approximate number of visitors in 1990 (in thousands) is:
\[ 29.39 \]
Now, addressing Part 2:
In 1990, the museum received approximately 29.39 thousand visitors.