What is 90% on the Z table?

1.645 Confidence (1–α) g 100% Significance α Critical Value Zα / 2 90% 0.10 1.645 95% 0.05 1.960 98% 0.02 2.326 99% 0.01 2.576

www2.southeastern.edu - Finding Z Alpha over 2

What causes poor confidence?

Causes of low self-esteem Unhappy childhood where parents (or other significant people such as teachers) were extremely critical. Poor academic...

Last updated Mar 20, 2021

How do I ask God for finances?

Prayer for Financial Breakthrough: Lord, thank you that you have entrusted me to manage and steward my finances with wisdom and diligence. Help me...

Last updated May 18, 2018

Awaken your dormant DNA ability to attract wealth effortlessly

The simple yet scientifically proven Wealth DNA method laid out in the report allows you to effortlessly start attracting the wealth and abundance you deserve.

Learn More »

Promotion

Return to Statistics Topics

Z Alpha Over Two (Z α/2 )

There are four ways to obtain the values needed for Z α/2 :

1) Use the normal distribution table (Table A-2 pp.724-25).

Example: Find Z α/2 for 90% confidence.

90% written as a decimal is 0.90.

1 – 0.90 = 0.10 = α and α/2 = 0.10/2 = 0.05. Look for 0.05 = 0.0500 or two numbers surrounding it in the body of Table A-2 (i.e. below the first row and to the right of the first column).

Since 0.0500 is less than 0.5, we look on page 724.

The number 0.0500 is not in the table, but it is between 0.0505 and 0.0495, which are in the table. is closer to 0.0500. 0.0505 – 0.0500 = 0.0005 and 0.0500 – 0.0495 = 0.0005.

Since the differences are equal, we average the corresponding standard scores.

Because 0.0505 is to the right of -1.6 and under 0.04, its standard score is -1.64. Because 0.0495 is to the right of -1.6 and under 0.05, its standard score is -1.65.

(-1.64 + (-1.65))/2 = -1.645

Thus Z α/2 = 1.645 for 90% confidence.

2) Use the t-Distribution table (Table A-3, p. 726).

Example: Find Z α/2 for 98% confidence.

98% written as a decimal is 0.98.

1 – 0.98 = 0.02 = a and α/2 = 0.01.

Find 0.01 in the “df” row at the top of page A12.

Z α/2 is the very last entry in the column under 0.01.

Hence Z α/2 = 2.326 for 98% confidence.

3) Use the TI 83/84 Calculator.

Example: Find Z α/2 for 99% confidence.

99% written as a decimal is 0.99.

1 – 0.99 = 0.01 = α and α/2 = 0.005.

Press “2ND” and “VARS” on your TI 83/84 calculator.

Choose “invNorm(” and press “ENTER”.

You should see “invNorm(” on your calculator screen.

Type in 0.005, add a right parenthesis and press the “ENTER” key.

The result, rounded to three decimal places, is the opposite of Z α/2 .

Consequently, Z α/2 = 2.576 for 99% confidence.

4) Memorize the values of Z α/2 .

The only confidence levels we use on tests or assignments are 90%, 95%, 98% and 99%, and the values of Z α/2 corresponding to these confidence levels are always the same. As a result, memorizing the necessary values of Z α/2 is fairly easy to do. Confidence (1–α) g 100% Significance α Critical Value Z α/2 90% 0.10 1.645 95% 0.05 1.960 98% 0.02 2.326 99% 0.01 2.576

Return to Statistics Topics

What is the lucky color for money?

Gold. According to Feng Shui principles, the colour gold can help manifest good luck and it also plays an important role in attracting money. Sep...

Last updated Aug 5, 2019

How do you practice the golden rule?

18 Practical Tips for Living the Golden Rule Practice empathy. Make it a habit to try to place yourself in the shoes of another person. ......

Last updated Jul 17, 2019

Awaken your dormant DNA ability to attract wealth effortlessly

The simple yet scientifically proven Wealth DNA method laid out in the report allows you to effortlessly start attracting the wealth and abundance you deserve.

Learn More »

Promotion

What is the vibration of Om?

The sound Om, when chanted, vibrates at the frequency of 432 Hz, which is the same vibrational frequency found throughout everything in nature. As such, AUM is the basic sound of the universe, so by chanting it, we are symbolically and physically acknowledging our connection to nature and all other living beings.

mindbodygreen.com - OM: What Does It Mean & Why Do We Chant It? - MindBodyGreen

Everything around us is pulsating and vibrating—nothing is really standing still. The sound Om, when chanted, vibrates at the frequency of 432 Hz, which is the same vibrational frequency found throughout everything in nature. As such, AUM is the basic sound of the universe, so by chanting it, we are symbolically and physically acknowledging our connection to nature and all other living beings. Physically, the act of chanting can also relax the body1 , slow down the nervous system, and calm the mind. Lastly, chanting AUM is a way to open and close a practice—to delineate it from the rest of our day and designate it as a special time in which we care for ourselves and practice being mindful. All in all, beginning and/or ending your spiritual practice with AUM can help you connect to it in a deeper way.

What color was Jesus skin most likely?

olive-colored Although not literally the face of Jesus, the result of the study determined that Jesus's skin would have been more olive-colored...

Last updated Oct 16, 2021

What keeps bugs away outside at night?

Light Citronella Candles and Torches Citronella plants produce an oil that serves as a natural insect repellent. You can light citronella candles...

Last updated May 18, 2019

Awaken your dormant DNA ability to attract wealth effortlessly

The simple yet scientifically proven Wealth DNA method laid out in the report allows you to effortlessly start attracting the wealth and abundance you deserve.

Learn More »

Promotion

What signs are very observant?

Overview: Virgos, like the other Earth signs, are incredibly grounded and hardworking. This sign is arguably the most observant zodiac, and notices...

Last updated Jun 7, 2022

Awaken your dormant DNA ability to attract wealth effortlessly

The simple yet scientifically proven Wealth DNA method laid out in the report allows you to effortlessly start attracting the wealth and abundance you deserve.

Learn More »

Promotion

How to build wealth through real estate?

7 Ways to Build Wealth Through Real Estate Investing Invest in a Private Equity Fund. Invest eligible capital gains in a Qualified Opportunity...

Last updated Mar 5, 2019