Question

Sarah used her calculator to work out the value of a number y .

Answer 1

Answer:

$7.75 \: \leqslant y \: < \: 7.85$

Step-by-step explanation:

The calculator approximated the value of y at 7.8.

We need to complete the error interval for y.

In other words, we calculate the upper and lower bound for y.

The level level of accuracy is to the nearest tenth.

To find the lower bound, we subtract half the degree of accuracy to get:

$y \geqslant 7.8 - 0.05 \\ y \geqslant 7.75$

To find the upper bound, add half the level of accuracy to get:

$y \: < \: 7.8 + 0.05 \\ y \: < \: 7.85$

Therefore the error interval is

$7.75 \: \leqslant y \: < \: 7.85$