Week 3_practice lab compute_gradient exercise 3

I am getting this error

 51     dj_db, dj_dw  = target(X, y, test_w, test_b)

—> 53 assert np.isclose(dj_db, 0.28936094), f"Wrong value for dj_db. Expected: {0.28936094} got: {dj_db}"
54 assert dj_dw.shape == test_w.shape, f"Wrong shape for dj_dw. Expected: {test_w.shape} got: {dj_dw.shape}"
55 assert np.allclose(dj_dw, [-0.11999166, 0.41498775, -0.71968405]), f"Wrong values for dj_dw. Got: {dj_dw}"

AssertionError: Wrong value for dj_db. Expected: 0.28936094 got: 0.309966650712056

the 1st cell is working fine but the second cell is giving error.

The test found an incorrect value for dj_db in your code.

I am unable to figure out the mistake in code ,the above cell is running fine. Can I send the code here ?

Please send it to me privately.