TOPIC 1
A representation of the population where one hopes to draw valid conclusions from about the population.
Sample
Locate the z-value that corresponds to TLE score of 98 given that mean is 68 and standard deviation is 38.
0.79
Find the probability of the area greater than z = 3.59
The following are MAPEH scores of HUMSS students in their Midterm exam: 1, 3, 5, 7, 9, 11, 13
Compute the population mean.
7
Give the formula in computing the population mean
the population mean is equal to the summation of x divided by the number of elements in the population
A technique used in selecting people or items for research.
Random Sampling
Locate the z-value that corresponds to score of 89 given that mean is 46 and standard deviation is 26.
1.65
Find the probability at most z = -2.73
0.32%
The following are MAPEH scores of HUMSS students in their Midterm exam: 1, 3, 5, 7, 9, 11, 13
Given population mean = 7
Compute the population variance.
16
Give the formula in computing sample mean
the sample mean is equal to the summation of x divided by the number of elements in the sample
A selection of n elements derived from a population N, which is the subject of the investigation, where each sample point has an equal chance of being selected using the appropriate sampling technique.
Given the mean μ = 88 and the standard deviation σ = 18 of a population of writing scores. Find the z-value that corresponds to a score x = 78
-0.56
Find the probability between z = -0.85 and z = 1.32
70.89%
The following are MAPEH scores of HUMSS students in their Midterm exam: 1, 3, 5, 7, 9, 11, 13
Given mean = 7, variance = 16
Compute the population standard deviation.
4
Give the formula in computing the sample variance.
the sample variance is equal to the summation of the quantity x minus sample mean squared divided by n minus 1
A sampling technique where every nth member of the population has an equal chance of being selected.
Simple Random Sampling
The heights of students in a class are normally distributed with a mean (μ) of 165 cm and a standard deviation (σ) of 8 cm. What is the Z-score for a student who is 150 cm tall?
-1.88
Find the probability between z = 2.66 and z = 3.77
0.38%
The following are the five scores of the students above that are randomly selected: 1, 3, 5, 7,9
Compute the sample mean.
5
Give the formula in computing the population variance.
the population variance is equal to the summation of the quantity of x minus population mean squared divided by N
A sampling technique in which members of the population are listed and samples are selected in intervals called sample intervals.
Systematic Random Sampling
The weights of packages shipped by a courier company are normally distributed with a mean (μ) of 12 kg and a standard deviation (σ) of 2.5 kg. Calculate the Z-score for a package weighing 15 kg.
1.2
Find the probability of the area no more than z = 2. 34
99.04%
The following are the five scores of the students above that are randomly selected: 1, 3, 5, 7,9
Given sample mean = 5
Compute the sample variance.
10
Give the formula in computing the population standard deviation.
the population standard deviation is equal to the square root of population variance
When members of the population have their names represented by small pieces of paper which are then mixed together and picked out at random. The selected members will be included in the sample.
Simple Random Sampling
What was the life span of a remote battery? If a costumer tested a sample of 148 and found out that its mean expectancy is 348, with a standard deviation of 68. Where one battery from the XYZ Company had a z-score of 18.8.
1626.4
Find the probability at least z = 0.98
16.35%
The following are TLE scores of TVL students in their Midterm exam: 10, 15, 20, 25, 30, 35, 40, 45
Compute the population mean.
27.5
Give the formula in computing the sample standard deviation.
the sample standard deviation is equal to the square root of sample variance
A sampling technique wherein the members of the population are grouped based on their homogeneity.
Stratified Random Sampling
A buyer tested a sample of 258 series lights. It found out that the mean life expectancy of the series lights was 958 h, with a standard deviation of 78. One particular series light from the ABC Company had a z-score of 4.80. What was the life span on this series light?
1332.4
Find the probability no more than z = 2.15
98.42%
The following are TLE scores of TVL students in their Midterm exam: 10, 15, 20, 25, 30, 35, 40, 45
Given population mean = 27.5
Compute the population variance.
131.25
Give the formula in computing the z-value
z is equal to x minus mean divided by standard deviation
It refers to the entire group that is under study or investigation.
Population
The systolic blood pressure of adults is normally distributed with a mean (μ) of 120 mmHg and a standard deviation (σ) of 15 mmHg. What is the systolic blood pressure (X) for someone with a Z-score of −1.4?
99
Find the probability between z = -0.45 and z = 1.34
58.35%
The following are the five scores of the students above that are randomly selected: 10, 15, 20, 25
Compute the sample mean.
17.5
Give the formula in computing the normal random variable.
x is equal to z-score times standard deviation plus mean
The sample is constructed by classifying the population into subpopulations or strata.
The lifespan of a brand of batteries is normally distributed with a mean (μ) of 1000 hours and a standard deviation (σ) of 50 hours. What is the lifespan (X) for a battery with a Z-score of −0.6?
970
Find the probability above z = -1.68
95.35%
The following are the five scores of the students above that are randomly selected: 10, 15, 20, 25
Given sample mean = 17.5
Compute the sample variance.
41.67
Is the probability distribution of continuous random variable.
Normal Probability Distribution
Imagine that you are all 60 in a class. You really wanted to draw 20 samples out of 60 students. So how are you going to do it?
Systematic Random Sampling
The weights of a type of fruit are normally distributed with a mean (μ) of 100 grams and a standard deviation (σ) of 15 grams. If the Z-score for a fruit is Z=−1.2, what is its weight (X)?
82
Find the probability between z = 1.75 and z = 1.82
0.57%
The measurement that describes the population is called Parameter, how about the measurement that describes the sample?
Statistic
1. Bell-shaped
2. Symmetrical about its center
3. Mean, median, and mode coincide at the center
4. Tails of the curve flatten out indefinitely along the horizontal axis but never touch it