Question

1. A research center claims that less than 50% of the US adults have accessed the internet over a wireless network with a laptop computer. In a random sample of 100 adults, 39% say that they have accessed the internet over a wireless network with a laptop computer. At α=0.01, is there enough evidence to support the researcher’s claim?

Answer 1

Solution :

This is the left tailed test .

The null and alternative hypothesis is

H₀ : p = 0.50

H_a : p < 0.50

n = 100

= 0.39

P₀ = 0.50

1 - P₀ = 1 - 0.50 = 0.50

Test statistic = z

= - P₀ / [P_{0 *} (1 - P₀ ) / n]

=0.39- 0.50 / [(0.50*0.50) / 100 ]

= -2.2

Test statistic = z = -2.2

P(z < -2.2 ) = 0.0139

P-value = 0.0139

= 0.01

P-value >

0.0139 > 0.01

Fail to reject the null hypothesis .

There is not sufficient evidence to suggest that