I need help.

Question

How you do it on a Ti-84 Caculator.

Answer 1

Note :

Using TI-84 calculator,

You need to type in your calculator as shown below.

invNorm(0.975, 0.1, 2517)

= 1.9599

= 23.458²

Then you will get 550.2984.

Answer 2

Step 1:

The standard deviation of selling prices for used two-year old Corvettes σ is $ 2517.

98 % confidence interval of sample mean is within $ 250.

Here margin of error E is 250.

Calculate the z score for 98 % confidence using Ti -84 calculator.

Follow these steps to evaluate z score for top 98 % confidence.

1.Select invNorm() in Ti -84 calculator.

[ 2nd --> VARS --> 3 ]

2.Enter area in decimals .

invNorm((1 - 0.98)/2)

invNorm(0.01)

3.Now press Enter in calculator to view answer

invNorm(0.01) = - 2.33.

|Z | score for 98 % confidence interval is 2.33.

Margin of error : ,

 

where Z is the Z-score for 98 % of confidence interval.

σ is the standard deviation

n is sample size.

Step 2:

Find the population mean .

Sample size of the selling prices for used two-year old Corvettes is 550.

Solution:

Sample size of the selling prices for used two-year old Corvettes is 550.