Question

Asked Jul 22, 2019

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A marketing manager for a cell phone company claims that more than 55% of children aged 8-12 have cell phones. In a survery of 802 children aged 8-12 by the National Consumers League, 449 of them had cell phones. Can you conclude that the managers claim is true? Use the 0.01 level of signifance.

Step 1

**Null and alternative hypotheses:**

Here, to check whether more than 55% of children aged 8-12 have cell phones, the appropriate test is **z-test for single sample proportion**.

The hypotheses for the test is given below.

*Null hypothesis:*

H_{0}: *p*_{0} = 0.55

*Alternative hypothesis:*

H_{1}: *p*_{0} > 0.55

**Sample proportion:**

The sample proportion is calculated as follows.

Step 2

**Computation of test statistic:**

The test statistic for z-test for single sample proportion is as follows.

Step 3

**Calculations:**

Here, *n* = 802.

The sample proportion, *p* = 0.5599.

The population proportion, *p*0 = 0.55.

The value of test stat...

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