Math Answers

Suppose that the mean weight of school children’s bookbags is 17.41 pounds, with a standard deviation of 2.2 pounds. Find the probability that the mean weight of a sample of 30 bookbags will exceed 17 pounds.

Many things closely follow a normal distribution. Give five examples of real-life data which follow this type of pattern. Example: heights of people

1. Teaching long division of 357÷19 for instrumental understanding

2. Teaching long division of 357÷19 for relational understanding

9. A garage offers a breakdown recovery service for motorists that is available every day of the

year. According to their records the number of call-outs they received per day last year were:

Number of call-outs: 0 1 2 3 4

Number of days: 68 103 145 37 12

Required: What is the probability that

A. They receive two call-outs in a day?

B. They receive two or fewer call-outs in a day?

C. They receive one or more call-outs in a day?

D. They receive less than four call-outs in a day?

E. They receive more than two call-outs in a day?

How would you use a teacher-centred media resource to explain the meaning of (7×8) to grade 5 learner? Use two different illustrations to show your understanding

A population consists of the four numbers 3 7 11 15 consider all possible sample of size two which can be drawn with replacement

Let A = {a, b, c}, B = {x, y}. Find the following:

1. A × B

2. B × A

Yna Celestine believes that the average amount of time spent by her classmates

in studying their self learning module in Math per week is less than 300 minutes

with a standard deviation of 45 minutes. She took a random sample of 35 students

in their class and found out that average time spent for studying was 285 minutes.

Test the claim at the 0.05 level of significance.

Consider the R −R2 function r r defined by   (t) = (a) Write down the domain of r (b) Is r (c) Is r continuous at t = 0? continuous at t = 2? (d) Sketch the curve r 26 . .  (t, t2) if t ∈ [−2,0] (t, t) t, t2 if if t ∈ (0,2) t ∈ [2,3]

the mean lifetime of a sample of 100 light tubes produced by a company is found to be 1,580 hours. Test the hypothesis at 5% level of significance that the mean lifetime of the tubes produced by the company is 1,600 hours with standard deviation of 90 hours