Statistics and Probability Answers

Which one of the following statement is correct. The mean of the sampling distribution is
1. Always equal to the mean of the population
2. Not equal to the mean of the population
3. The square root of the sample size
4. Als called the standard error
5. Not normally distributed

If Z is normally distributed with a mean u=0 the variance a=1 calculate P (Z-1.67)
1. 0.9525
2. 0.0475
3. 0.0548
4. 0.7486
5. 0.9608

For a discrete random variable that is poission distributed with a mean i=20 which one of the following statement is incorrect
1. P (X=0)
2. P (X-0 )
3. P (X-1)
4. P (X-7)
5. The variance a is 4

Six trial are conducted in abinomial process in who the probability of success in a given trial is 0.25 .If x= the number of the following statement is incorrect
1. The mean u=15
2. The standard deviation a=1.125
3. P (X=3)
4. P (X-4)
5. P (X-2)

Consider events A and B are mutually exclusive, P(A)= 0.3 and P (B=0.6, p (A or B) is
1. 0.18
2. 0.09
3. 0
4. 0.9
5 0.3

Attempting to analyze the relationship between advertising (X) and sales (Y) the owner of a furnitures store recorded the monthly advertising buget ( Rand thousands ) and the sales (Rand Millions ) for sample of 6 months
X- 23, 46, 60, 54, 28 ,33
Y- 96, 11.3 ,12.8 , 98 ,89 , 12.5
Which one of the following statements is incorrect
1. X = 40.67 Y=10.82
2. X represent the depend variable
3. b1= 8.624
4. b1= 0.054
5. The equation line us y= 8.624 + 0.054 X

Consider the following data value of variable X and Y. X- 5, 4 ,3 , 6, 9, 8, 10, 45. Y- 7, 8, 10, 5, 2, 3, 1, 36
Which one of the following statement is correct?
1. X represents the dependent variable
2. Y represents the independen variable
3. 55x = -25,429
4.55x = 41,147
5 The slope is bi = -1,257

An electronics store has 500 smartphones in stock. Each customer who enters the store can buy as many smartphones as they want, while supplies last. Let Xi be the number of smartphones desired by customer i. Based on their market research, the store knows that the distribution of the number of smartphones desired by a customer has a mean of 0.85 and a standard deviation of 0.6. If 625 customers enter the store today, what is the probability that they will all be able to purchase the smartphones they desire?

The average time for a courier to travel from Manila to Pampanga is 200 minutes, and the standard deviation is 10 minutes. If one of these trips is selected at random, find the probability that a courier will have the following travel time: a. At least 180 minutes b. At most 205 minutes

If the systolic blood pressure for a certain group of obese people has a mean of 135 and a standard deviation of 8, find the probability that a randomly selected person will have the following blood pressure: a. Above 152 b. Below 138 c. Between 128 and 167