In this worksheet you will learn to use the function "TDIST".
This function is the t-distribution equivalent of the function "NORMSDIST" .
 

Here are the information about "TDIST " from the Excel Help:

TDIST

Returns the Percentage Points (probability) for the Student t-distribution where a numeric value (x) is a calculated
value of t for which the Percentage Points are to be computed. The t-distribution is used in the hypothesis testing
of small sample data sets. Use this function in place of a table of critical values for the t-distribution.

Syntax

TDIST(x,degrees_freedom,tails)

X   is the numeric value at which to evaluate the distribution.

Degrees_freedom   is an integer indicating the number of degrees of freedom.

Tails   specifies the number of distribution tails to return. If tails = 1, TDIST returns the one-tailed distribution. If tails = 2, TDIST returns the two-tailed distribution.

Remarks

If any argument is nonnumeric, TDIST returns the #VALUE! error value.
 

If degrees_freedom < 1, TDIST returns the #NUM! error value.
 

The degrees_freedom and tails arguments are truncated to integers.
 

If tails is any value other than 1 or 2, TDIST returns the #NUM! error value.
 

TDIST is calculated as TDIST = p( x<X ), where X is a random variable that follows the t-distribution.

Example

TDIST(1.96,60,2) equals 0.054645, or 5.46 percent
 

On row 1 of a new worksheet copy the row corresponding to d.o.f. = 6 from the t-distribution
table at page T11 of the textbook.  Then on the row 3 recover the tail probabilities from the header of the
table using the function TDIST.  You should get a table like:

Note!  As you observe the values computed in row 3 are slightly different from the probabilities listed in the header row of
the table T11.  These differences are due to the 3 decimals approximations used in listing the t-values.
           You may use the function TIINV to compute the  t-values with better precision.  See Exercise 7.16 .

You should use the function TDIST to compute the exact P-values of tests for small SRS taken from populations with approximately
normal distributions.

Questions:

Hand in one page Excel printout containing:

1)  a  table like above.

2) the exact answer to Ex. 7.13 (e) in the cell A5 (with 5 decimals).

3) the exact answer to Ex. 7.14 (c) in the cell A7 (with 5 decimals).