Questions: A popcorn company finds that their 1 kg bags have a mean of 1,040 grams with a standard deviation of 25 grams.
What is the z-score for a bag weighing 975 grams? Round your answer to the nearest tenth.
Transcript text: A popcorn company find that their 1 kg bags have a mean of $1,040 \mathrm{grams}$ with a standard deviation of 25 grams.
What is the $z$-score for a bag weighing 975 grams?
Round your answer to the nearest tenth.
Solution
Solution Steps
Step 1: Understand the Problem
We need to find the \( z \)-score for a bag of popcorn weighing 975 grams, given that the mean weight of the bags is 1040 grams with a standard deviation of 25 grams.
Step 2: Use the Z-score Formula
The formula for calculating the \( z \)-score is:
\[
z = \frac{X - \mu}{\sigma}
\]
where:
\( X \) is the value for which we are calculating the \( z \)-score (975 grams),
\( \mu \) is the mean of the distribution (1040 grams),
\( \sigma \) is the standard deviation of the distribution (25 grams).
Step 3: Substitute the Values
Substitute the given values into the formula:
\[
z = \frac{975 - 1040}{25}
\]
Step 4: Calculate the Z-score
Perform the calculation:
\[
z = \frac{-65}{25} = -2.6
\]
Final Answer
The \( z \)-score for a bag weighing 975 grams is \(\boxed{-2.6}\).