Answer:
For the 99th percentile, we have X = 206 seconds.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

99th percentile:
Value of X when Z has a pvalue of 0.99. So we use 




For the 99th percentile, we have X = 206 seconds.
Answer:
21
Step-by-step explanation:

Answer:
Length =
= 5/2 inches or 2 1/2 inches
Step-by-step explanation:
Lin lines the bottom of her first pan with aluminum foil. The area of the rectangular piece of foil 11 1 4 is square inches. Its length is 4 1 2 inches. What is the width of the foil? Explain your reasoning.
Area of rectangle = Length × Width
Widths = Area/Length
The area of the rectangular piece of foil 11 1/4 is square inches.
Its length is 4 1 /2 inches.
Hence:
Length = 11 1/4 /4 1/2
= 45/4 ÷ 9/2
= 45/4 × 2/9
= 5/2 inches
= 2 1/2 inches
Answer:
x = 7
General Formulas and Concepts:
Order of Operations: BPEMDAS
Step-by-Step Explanation:
Step 1: Define
5(x - 3) = 2(x + 3)
Step 2: Solve for x
1. Distribute: 5x - 15 = 2x + 6
2. Subtract 2x on both sides: 3x - 15 = 6
3. Add 15 on both sides: 3x = 21
4. Divide both sides by 3: x = 7