Review from ISDS 361A

ISDS 361B Review From ISDS 361A

1. Normal Distribution by Excel NORMDIST (x, µ, σ, TRUE) gives ______

NORMSDIST(z) gives ______

NORMINV(p, µ, σ) gives ______

NORMSINV(p) gives ______

2. Confidence Intervals and Hypothesis Tests for µ NECESSARY CONDITION

Either (1) ______OR (2) ______

3. Confidence Intervals and Hypothesis Tests for µ -- When to use z and when to use t

If the necessary condition holds, then,

Use z if ______Standard Error = ______

Use t if ______Standard Error = ______

4. Confidence Intervals for µ

General Form: ______

Sampling from normal or large n and σ known: ______

Excel: = ______

Sampling from normal or large n and σ unknown:

Excel: = ______5. Hypothesis Tests for µ

 Meaning of α: ______

 Meaning of p-value: ______

6. Rejection Region Approach

σ Known

Calculate z = ______

Cases: H1: µ > µ0 Reject H0 (Accept H1) if z ______

H1: µ < µ0 Reject H0 (Accept H1) if z ______

H1: µ ≠ µ0 Reject H0 (Accept H1) if z ______or if z ______

σ Unknown

Calculate t = ______

Cases: Degrees of Freedom = n-1

H1: µ > µ0 Reject H0 (Accept H1) if t ______

H1: µ < µ0 Reject H0 (Accept H1) if t ______

H1: µ ≠ µ0 Reject H0 (Accept H1) if t ______or if t ______7. p-Value Approach Reject H0 (Accept H1) if p is low (< α)

σ Known

Calculate z = ______

Cases: H1: µ > µ0 p = ______EXCEL: ______

H1: µ < µ0 p = ______EXCEL: ______

H1: µ ≠ µ0 If z > 0: p = ______EXCEL: ______

If z < 0; p = ______EXCEL: ______

σ Unknown

Calculate t = ______

EXCEL: DATA ANALYSIS/DESCRIPTIVE STATISTICS. Then,

t = ______

Cases: Degrees of Freedom = n-1

H1: µ > µ0 p = ______EXCEL: (Assumes t > 0) ______

H1: µ < µ0 p = ______EXCEL: (Assumes t < 0) ______

H1: µ ≠ µ0 If t > 0: p = ______EXCEL: ______

If t < 0: p = ______EXCEL: ______Sample Questions:

1. Can you conclude that the average electric bill for residential customers in Mission Viejo in July > $150?

2. Give a 99% confidence interval for average amount spent by teenagers in Orange County each month on CD's.

3. Last year the average driving time from Fullerton to Mission Viejo was 40 minutes with a standard deviation of 6 minutes. Assuming that the standard deviation has not changed, can you conclude the average driving time has changed from last year?

4. Can you conclude that the average time spent waiting in the drive-thru line at the Jack-In-The-Box on the corner of Avery and the 5 Freeway is less than 3 minutes?

5. Assuming that the standard deviation is 9 yards, give a 95% confidence interval for the average distance Tiger Woods drives a golf ball.

6. Assuming a standard deviation of $.06 per gallon, can you conclude that the average price for regular unleaded gasoline in Orange County on January 20 was greater than $3.30?