Lenders tighten or loosen their standards for issuing credit as economic conditions change. One of the criteria lenders use to evaluate the creitworthiness of a potential borrower is his credit risk score, usually a FICO score. FICO scores range from 300 to 850. A consumer with a high FICO score is perceived to be a low credit risk to the lender and is more likely to be extended credit than a consumer with a low score. A credit card represents a line of credit, because the credit card holder obtains a loan whenever the card is used to pay for a purchase. A study of credit card accounts opened in 2002 found a mean FICO score for the credit card holder (at the time the card was issued) of 731 and a standard deviation of 76.

You conduct a hypothesis test to determine whethere banks have tightened their standards for issuing credit cards since 2002. You collect a random sample of 64 credit cards issued during the past 6months. The sample mean FICO score of the credit card holders (at the time their cards were issued) is x=745. Assume that the standard deviation of the population of FICO score for credit cards issed during the past 6months is known to be \sigma+76, the standard deviation from the NBER study.

Let \mu equal the true population mean FICO score for the consumers issued credit cards in the past 6 months. You should formulate the null and alternative hypotheses as( H\sigma: \mu is greater than 731, Ha: \mu is less than or equal to 731. H\sigma: X is less than or equal to 731, Ha: X is greater than 731 H\sigma: \mu is greater than or equal to 731, Ha: \mu is less than 731 H\sigma: \mu is less than or equal to 731, Ha: \mu is greater than 731)

If the null hypothese is true as an equality, the sampling distribution of X is approximated by ( a T, a binonmial, a standard normal, a normal, an unknown) distribution with ( a mean of 745, an unknown mean, a mean of 731, a mean of 0) and a standard deviation of (9.5, 76, uknown, 1.0)

You conduct the hypotheses test uding a significance level of \sigma=.10 According to the critical value approach, when do you reject the null hypothessis. You reject the hypothesies when ( Reject if H\sigma if Z less than or equal to 1.47 . Reject if H\sigma if Z is greather than or equal to 1.282. Reject if H\sigma if Z is greater than or equal to 1.282. Reject if H\sigma if Z is less than or equal to -1.645 or Z greater than or equal to 1.645). The P Value is . Using the P value approach the null hypotheses is (rejected or not rejected). Using the critical value apprach the null hypotheses is (rejected, is not rejected).Can you or can you not conclude that the banks have tightened their standards for issuing credit cards since 2002.