Solved on Jan 21, 2024
Find the probability that a randomly selected thermometer reading is less than Celsius, given the readings are normally distributed with Celsius and Celsius.
STEP 1
Assumptions
1. The readings at freezing on a bundle of thermometers are normally distributed.
2. The mean of the distribution is Celsius.
3. The standard deviation of the distribution is Celsius.
4. We are looking for the probability of a single reading being less than Celsius.
STEP 2
To find the probability of a reading being less than Celsius, we need to standardize this value using the Z-score formula. The Z-score is the number of standard deviations a data point is from the mean.
Where is the value from the normal distribution, is the mean, and is the standard deviation.
STEP 3
Now, plug in the values for , , and to calculate the Z-score for Celsius.
STEP 4
Calculate the Z-score.
STEP 5
Now that we have the Z-score, we can find the probability of a reading being less than Celsius by looking up this Z-score in the standard normal distribution table, which gives the probability that a standard normal variable is less than .
STEP 6
If a standard normal distribution table is not available, we can use a calculator or software that provides the cumulative distribution function (CDF) for the standard normal distribution. The CDF will give us the probability that a standard normal variable is less than or equal to our Z-score.
STEP 7
Using the CDF of the standard normal distribution, we find the probability corresponding to the Z-score of .
STEP 8
The probability of reading less than Celsius is the value obtained from the CDF of the standard normal distribution at .
Let's denote this probability as .
STEP 9
After finding the probability from the CDF or the standard normal distribution table, we have our final answer.
The probability of a thermometer reading less than Celsius is .
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