Suppose that the germination periods, in days, for grass seed are normally distributed with an unknown mean and standard deviation. The germination periods of40

randomly sampled types of grass seed are used to estimate the mean of the population. Whatt

-score should be used to find the80%

confidence interval for the population mean?

df

...

38

39

40

41

42

t

0.10

...

1.304

1.304

1.303

1.303

1.302

t

0.05

...

1.686

1.685

1.684

1.683

1.682

t

0.025

...

2.024

2.023

2.021

2.020

2.018

t

0.01

...

2.429

2.426

2.423

2.421

2.418

t

0.005

...

2.712

2.708

2.704

2.701

2.698

Use the portion of the table above or a calculator. If you use a calculator, round your answer to three decimal places.

Provide your answer below: