W=4 that the answer !!!!!
Answer:
Z = (42-20)/4 = 5.5
Z = X-μ / σ
Step-by-step explanation:
Answer:
x = ± ![\sqrt{7}](https://tex.z-dn.net/?f=%5Csqrt%7B7%7D)
Step-by-step explanation:
To find the zeros equate the polynomial to zero, that is
x² - 7 = 0 ( add 7 to both sides )
x² = 7 ( take the square root of both sides )
x = ±
Thus the exact solutions are
x = -
, x = ![\sqrt{7}](https://tex.z-dn.net/?f=%5Csqrt%7B7%7D)