How to Use the Z | how to read z table
WhatisP(Z≤1.5)?Answer:0.9332Tofindtheanswerusingthez-table,findwheretherowfor1.5intersectswiththecolumnfor0.00;thisvalueis0.9332.Thez-tableshowsonly"lessthan"probabilitiessoitgivesyouexactlywhatyouneedforthisquestion.Note:Noprobabilityisexactlyatonesinglepoint,so:P(Z≤1.5)=P(Z<1.5)WhatisP(Z≥1.5)?Answer:0.0668Usethez-tabletofindwheretherowfor1.5intersectswiththecolumnfor0.00,whichis0.9332.Becausethez-tablegivesyouonly"lessthan"probabilities,subtractP(Z<1.5)from1(rememberthatthetotalproba...
What is P (Z ≤ 1.5) ?
Answer: 0.9332
To find the answer using the z-table, find where the row for 1.5 intersects with the column for 0.00; this value is 0.9332. The z-table shows only "less than" probabilities so it gives you exactly what you need for this question. Note: No probability is exactly at one single point, so:
P (Z ≤ 1.5) = P (Z < 1.5)What is P (Z ≥ 1.5) ?
Answer: 0.0668
Use the z-table to find where the row for 1.5 intersects with the column for 0.00, which is 0.9332. Because the z-table gives you only "less than" probabilities, subtract P(Z < 1.5) from 1 (remember that the total probability for the normal distribution is 1.00, or 100%):
P (Z ≥ 1.5) = 1 – P (Z < 1.5)= 1 – 0.9332 = 0.0668
What is P (–0.5 ≤ Z ≤ 1.0) ?
Answer: 0.5328