Statistics and Probability Answers

The score 28 and 40 bound the middle 95% of the distribution. What percent is left at the tails of the distribution

A local political leader claims that 95% of the families in his area of responsibility 

were given “ayuda” during a one-month lockdown. Of a random sample of 200 families, 187 said they received relief or “ayuda”. Is this enough to affirm the 

leader’s claim? Use 𝑎 = 0.05.

It is a point such that 90% of the distribution lies below it and 10% lies above

1. The average score in the entrance examination in Mathematics at Sto.

Rosario National High School is 80 with a standard deviation of 10.A

random of 40 students was taken from this year's examinees and

was found to have a mean score of 84.

Is there a significant difference between the known mean and the

sample mean? Test at a= 0.05

Solution :

Step 1. H0: = 80 : There is no significant difference

hypothesized and the sample mean.

H1: "\\neq" 80 :

Step 2. Level of significance. a = 0.05.

Step 3. two tailed test, find the critical value. Zt =

4. Compute the test-statistic value:

5. Step :

6. Conclusion:

. Consider Interest centers on the life of an electronic component. Suppose it is known that the probability that the component survives for more than 6000 hours is 0.42. Suppose also that the probability that the component survives no longer than 4000 hours is 0.04. Determine the Probability that;

(a) The life of the component is less than or equal to 6000 hours?

(b)The life is greater than 4000 hours? 

According to a genetics theory,a certain cross of guinea pigs will result in red,black, and white offspring in the ratio 8:4:4.Find the probability that among 8 offspring,5 will be red,2 black, and 1 white.

Off-road motorbike racing can be dangerous, especially when it rains. It has been found that it rains during

18% of races. When it does not rain, there is a 5% chance that Dwayne (a rider) will get hurt. However, when it

rains, the chance that he gets hurt increases to 35%. Dwayne has just finished a race and is hurt. What is the

probability that it rained during the race?

QUESTION: A study believes that 70% of adults in the Philippines own a cellphone.

A cellphone manufacturer believes that the actual number is much

less than 70%. 100 Filipino adults were surveyed, of which 74 have

cellphones. Using a 5% level of significance, is the cellphone

manufacturer’s claim valid or not?

CLAIM:

EVIDENCE:

REASONING: