Find the level of confidence assigned to an interval estimat

Find the level of confidence assigned to an interval estimate of the mean formed using the following intervals. (Give your answers as whole numbers.)

(a)

x 1.28 · _{_x} to x + 1.28 · _{_x}

(b)

x 1.44 · _{_x} to x + 1.44 · _{_x}

(c)

x 1.96 · _{_x} to x + 1.96 · _{_x}

(d)

x 2.33 · _{_x} to x + 2.33 · _{_x}

(a)

x 1.28 · x to x + 1.28 · x

confidence interval: 80%

(b)

x 1.44 · x to x + 1.44 · x

confidence interval:85%

(c)

x 1.96 · x to x + 1.96 · x

confidence interval: 95%

(d)

x 2.33 · x to x + 2.33 · x

confidence interval: 98%