Question

answer in the simpilest way


A keyboarding instructor wants to test if a new method of instruction is ​effective.
​
​With the old method students typed a mean of
words per ​minute with a standard deviation of
words per minute.
​
​Thirty students ​selected at random received instruction using the new method and were ​then given a typing test.
​
​The mean and standard deviation of the typing ​speeds of the
students was approximately
and
, respectively.
​
​Would you conclude the new method of instruction is effective in increasing ​the number of words per minute?
​
​Explain your answer.

Answer 1

I can help — but the problem is missing the numbers. I need:
- old method mean (μ0)
- old method standard deviation (if this is the population SD or just historical sample SD)
- sample size (you said 30)
- new-method sample mean (x̄)
- new-method sample standard deviation (s)
- significance level (α) if you have one (commonly 0.05)

If you give those, I will compute and state the conclusion.

If you want the procedure now (simple steps):
1. Hypotheses: H0: μ = μ0 (no increase) vs Ha: μ > μ0 (increase).
2. Use t-test (n=30, use t unless population SD is known). Test statistic: t = (x̄ − μ0) / (s/√n).
3. Find p-value = P(T_{n−1} ≥ t). If p-value < α, reject H0 (conclude method is effective); otherwise do not reject H0.
4. State conclusion in plain words.

Give the numbers and I’ll do the calculation and conclusion.