Question

Find the number C such that P(X < C) = .01 where X is distributed according to t(14) (t-distribution with 14 degrees of freedom)

Group of answer choices

C = -2.624

C = 2.624

C = 2.602

C = -2.602

Answer 1

Solution:

Given:

df = 14

P( X < C )= 0.01

We have to find value of C using t distribution.

P( X < C )= 0.01 that means, area below C is 0.01

thus this C value is in left tail , thus C value would be negative.

Look in t table for df = 14 and one tail ( left tail) area = 0.01

C = 2.624

but since this is in left tail, so C value would be negative

that is:

C = -2.624

Thus correct answer is:

C = -2.624

We can use Excel command also:

=T.INV(probability , df)

=T.INV(0.01,14)

=-2.624

Thus C = -2.624