A random sample of 149 recent donations at a certain blood bank reveals that 84 were type A blood. Does this suggest that the actual percentage of type A donations differs from 40%, the percentage of the population having type A blood? Carry out a test of the appropriate hypotheses using a significance level of 0.01.
State the appropriate null and alternative hypotheses.
H0: p = 0.40
Ha: p < 0.40H0:
p = 0.40
Ha: p ≠
0.40 H0: p ≠
0.40
Ha: p = 0.40H0:
p = 0.40
Ha: p > 0.40
Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to four decimal places.)
z = _______.
P-Value = _______.
State the conclusion in the problem context.
Reject the null hypothesis. There is sufficient evidence to conclude that the percentage of type A donations differs from 40%.Reject the null hypothesis. There is not sufficient evidence to conclude that the percentage of type A donations differs from 40%. Do not reject the null hypothesis. There is sufficient evidence to conclude that the percentage of type A donations differs from 40%.Do not reject the null hypothesis. There is not sufficient evidence to conclude that the percentage of type A donations differs from 40%.
Would your conclusion have been different if a significance level of 0.05 had been used?
The null and alternative hypothesis are
H0: p = 0.40
Ha: p 0.40
Sample proportion = 84 / 149 = 0.5638
Test statistics
z = - p / sqrt( p (1 - p) / n)
= 0.5638 - 0.40 / sqrt(0.40 * ( 1 - 0.40) / 149)
= 4.08
p-value = 2 * P(Z > z) (Since this is two tailed test, p-value is double of probability)
= 2 * P(Z > 4.08)
= 2 * 0
= 0
Since p-value < 0.01 level reject H0.
Reject the null hypothesis. There is sufficient evidence to conclude that the percentage of type A
donations differs from 40%
Get Answers For Free
Most questions answered within 1 hours.