shaniab we also have to simplify and show!
$$3 \frac{2}{7} + 1\frac{4}{7}$$
now multiply the whole number with the denominator and add the numerator!
$$=\frac{23}{7} + \frac{11}{7}$$
as we have same denominators well just add the numerators!
$$=\frac{34}{7}$$
now i hope you can convert it into decimal!